[RFC PATCH-tip v4 00/10] locking/rwsem: Enable reader optimistic spinning

[RFC PATCH-tip v4 00/10] locking/rwsem: Enable reader optimistic spinning

[Waiman Long]

v3->v4:
 - Rebased to the latest tip tree due to changes to rwsem-xadd.c.
 - Update the OSQ patch to fix race condition.

v2->v3:
 - Used smp_acquire__after_ctrl_dep() to provide acquire barrier.
 - Added the following new patches:
   1) make rwsem_spin_on_owner() return a tristate value.
   2) reactivate reader spinning when there is a large number of
      favorable writer-on-writer spinnings.
   3) move all the rwsem macros in arch-specific rwsem.h files
      into a common asm-generic/rwsem_types.h file.
   4) add a boot parameter to specify the reader spinning threshold.
 - Updated some of the patches as suggested by PeterZ and adjusted
   some of the reader spinning parameters.

v1->v2:
 - Fixed a 0day build error.
 - Added a new patch 1 to make osq_lock() a proper acquire memory
   barrier.
 - Replaced the explicit enabling of reader spinning by an autotuning
   mechanism that disable reader spinning for those rwsems that may
   not benefit from reader spinning.
 - Remove the last xfs patch as it is no longer necessary.

This patchset enables more aggressive optimistic spinning on
both readers and writers waiting on a writer or reader owned
lock. Spinning on writer is done by looking at the on_cpu flag of the
lock owner. Spinning on readers, on the other hand, is count-based as
there is no easy way to figure out if all the readers are running. The
spinner will stop spinning once the count goes to 0. Because of that,
spinning on readers may hurt performance in some cases.

An autotuning mechanism is used to determine if a rwsem can benefit
from reader optimistic spinning. It will maintain reader spinning as
long as no less than 80% of the spins are successful.

Patch 1 updates the osq_lock() function to make it a proper acquire
memory barrier.

Patch 2 reduces the length of the blocking window after a read locking
attempt where writer lock stealing is disabled because of the active
read lock. It can improve rwsem performance for contended lock. It is
independent of the rest of the patchset.

Patch 3 modifies rwsem_spin_on_owner() to return a tri-state value
that can be used in later patch.

Patch 4 puts in place the autotuning mechanism to check if reader
optimistic spinning should be used or not.

Patch 5 moves down the rwsem_down_read_failed() function for later
patches.

Patch 6 moves the macro definitions in various arch-specific rwsem.h
header files into a commont asm-generic/rwsem_types.h file.

Patch 7 changes RWSEM_WAITING_BIAS to simpify reader trylock code.

Patch 8 enables readers to do optimistic spinning.

Patch 9 allows reactivation of reader spinning when a lot of
writer-on-writer spins are successful.

Patch 10 adds a new boot parameter to change the reader spinning
threshold which can be system specific.

Waiman Long (10):
  locking/osq: Make lock/unlock proper acquire/release barrier
  locking/rwsem: Stop active read lock ASAP
  locking/rwsem: Make rwsem_spin_on_owner() return a tri-state value
  locking/rwsem: Enable count-based spinning on reader
  locking/rwsem: move down rwsem_down_read_failed function
  locking/rwsem: Move common rwsem macros to asm-generic/rwsem_types.h
  locking/rwsem: Change RWSEM_WAITING_BIAS for better disambiguation
  locking/rwsem: Enable spinning readers
  locking/rwsem: Enable reactivation of reader spinning
  locking/rwsem: Add a boot parameter to reader spinning threshold

 Documentation/kernel-parameters.txt |    3 +
 arch/alpha/include/asm/rwsem.h      |   11 +-
 arch/ia64/include/asm/rwsem.h       |    9 +-
 arch/s390/include/asm/rwsem.h       |    9 +-
 arch/x86/include/asm/rwsem.h        |   22 +---
 include/asm-generic/rwsem.h         |   20 +--
 include/asm-generic/rwsem_types.h   |   28 ++++
 include/linux/rwsem.h               |   23 +++-
 kernel/locking/osq_lock.c           |   24 ++-
 kernel/locking/rwsem-xadd.c         |  296 ++++++++++++++++++++++++++---------
 10 files changed, 308 insertions(+), 137 deletions(-)
 create mode 100644 include/asm-generic/rwsem_types.h

[RFC PATCH-tip v4 01/10] locking/osq: Make lock/unlock proper acquire/release barrier

[Waiman Long]

The osq_lock() and osq_unlock() function may not provide the necessary
acquire and release barrier in some cases. This patch makes sure
that the proper barriers are provided when osq_lock() is successful
or when osq_unlock() is called.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
---
 kernel/locking/osq_lock.c |   24 ++++++++++++++++++------
 1 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
index 05a3785..3da0b97 100644
--- a/kernel/locking/osq_lock.c
+++ b/kernel/locking/osq_lock.c
@@ -124,6 +124,11 @@ bool osq_lock(struct optimistic_spin_queue *lock)
 
 		cpu_relax_lowlatency();
 	}
+	/*
+	 * Add an acquire memory barrier for pairing with the release barrier
+	 * in unlock.
+	 */
+	smp_acquire__after_ctrl_dep();
 	return true;
 
 unqueue:
@@ -198,13 +203,20 @@ void osq_unlock(struct optimistic_spin_queue *lock)
 	 * Second most likely case.
 	 */
 	node = this_cpu_ptr(&osq_node);
-	next = xchg(&node->next, NULL);
-	if (next) {
-		WRITE_ONCE(next->locked, 1);
+	next = xchg_relaxed(&node->next, NULL);
+	if (next)
+		goto unlock;
+
+	next = osq_wait_next(lock, node, NULL);
+	if (unlikely(!next)) {
+		/*
+		 * In the unlikely event that the OSQ is empty, we need to
+		 * provide a proper release barrier.
+		 */
+		smp_mb();
 		return;
 	}
 
-	next = osq_wait_next(lock, node, NULL);
-	if (next)
-		WRITE_ONCE(next->locked, 1);
+unlock:
+	smp_store_release(&next->locked, 1);
 }
-- 
1.7.1

Re: [RFC PATCH-tip v4 01/10] locking/osq: Make lock/unlock proper acquire/release barrier

[Davidlohr Bueso]

On Thu, 18 Aug 2016, Waiman Long wrote:

>The osq_lock() and osq_unlock() function may not provide the necessary
>acquire and release barrier in some cases. This patch makes sure
>that the proper barriers are provided when osq_lock() is successful
>or when osq_unlock() is called.

But why do we need these guarantees given that osq is only used internally
for lock owner spinning situations? Leaking out of the critical region will
obviously be bad if using it as a full lock, but, as is, this can only hurt
performance of two of the most popular locks in the kernel -- although yes,
using smp_acquire__after_ctrl_dep is nicer for polling.

If you need tighter osq for rwsems, could it be refactored such that mutexes
do not take a hit?

>
>Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
>Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
>---
> kernel/locking/osq_lock.c |   24 ++++++++++++++++++------
> 1 files changed, 18 insertions(+), 6 deletions(-)
>
>diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
>index 05a3785..3da0b97 100644
>--- a/kernel/locking/osq_lock.c
>+++ b/kernel/locking/osq_lock.c
>@@ -124,6 +124,11 @@ bool osq_lock(struct optimistic_spin_queue *lock)
>
> 		cpu_relax_lowlatency();
> 	}
>+	/*
>+	 * Add an acquire memory barrier for pairing with the release barrier
>+	 * in unlock.
>+	 */
>+	smp_acquire__after_ctrl_dep();
> 	return true;
>
> unqueue:
>@@ -198,13 +203,20 @@ void osq_unlock(struct optimistic_spin_queue *lock)
> 	 * Second most likely case.
> 	 */
> 	node = this_cpu_ptr(&osq_node);
>-	next = xchg(&node->next, NULL);
>-	if (next) {
>-		WRITE_ONCE(next->locked, 1);
>+	next = xchg_relaxed(&node->next, NULL);
>+	if (next)
>+		goto unlock;
>+
>+	next = osq_wait_next(lock, node, NULL);
>+	if (unlikely(!next)) {
>+		/*
>+		 * In the unlikely event that the OSQ is empty, we need to
>+		 * provide a proper release barrier.
>+		 */
>+		smp_mb();
> 		return;
> 	}
>
>-	next = osq_wait_next(lock, node, NULL);
>-	if (next)
>-		WRITE_ONCE(next->locked, 1);
>+unlock:
>+	smp_store_release(&next->locked, 1);
> }

As well as for the smp_acquire__after_ctrl_dep comment you have above, this also
obviously pairs with the osq_lock's smp_load_acquire while backing out (unqueueing,
step A). Given the above, for this case we might also just rely on READ_ONCE(node->locked),
if we get the conditional wrong and miss the node becoming locked, all we do is another
iteration, and while there is a cmpxchg() there, it is mitigated with the ccas thingy.

Thanks,
Davidlohr

Re: [RFC PATCH-tip v4 01/10] locking/osq: Make lock/unlock proper acquire/release barrier

[Jason Low]

On Tue, Oct 4, 2016 at 12:06 PM, Davidlohr Bueso <dave@stgolabs.net> wrote:
> On Thu, 18 Aug 2016, Waiman Long wrote:
>
>> The osq_lock() and osq_unlock() function may not provide the necessary
>> acquire and release barrier in some cases. This patch makes sure
>> that the proper barriers are provided when osq_lock() is successful
>> or when osq_unlock() is called.
>
>
> But why do we need these guarantees given that osq is only used internally
> for lock owner spinning situations? Leaking out of the critical region will
> obviously be bad if using it as a full lock, but, as is, this can only hurt
> performance of two of the most popular locks in the kernel -- although yes,
> using smp_acquire__after_ctrl_dep is nicer for polling.
>
> If you need tighter osq for rwsems, could it be refactored such that mutexes
> do not take a hit?

I agree with David, the OSQ is meant to be used internally as a
queuing mechanism than as something for protecting critical regions,
and so these guarantees of preventing critical section leaks don't
seem to be necessary for the OSQ. If that is the case, then it would
be better to avoid the performance hit to mutexes and rwsems.

Jason

Re: [RFC PATCH-tip v4 01/10] locking/osq: Make lock/unlock proper acquire/release barrier

[Waiman Long]

On 10/04/2016 03:06 PM, Davidlohr Bueso wrote:
> On Thu, 18 Aug 2016, Waiman Long wrote:
>
>> The osq_lock() and osq_unlock() function may not provide the necessary
>> acquire and release barrier in some cases. This patch makes sure
>> that the proper barriers are provided when osq_lock() is successful
>> or when osq_unlock() is called.
>
> But why do we need these guarantees given that osq is only used 
> internally
> for lock owner spinning situations? Leaking out of the critical region 
> will
> obviously be bad if using it as a full lock, but, as is, this can only 
> hurt
> performance of two of the most popular locks in the kernel -- although 
> yes,
> using smp_acquire__after_ctrl_dep is nicer for polling.

First of all, it is not obvious from the name osq_lock() that it is not 
an acquire barrier in some cases. We either need to clearly document it 
or has a variant name that indicate that, e.g. osq_lock_relaxed, for 
example.

Secondly, if we look at the use cases of osq_lock(), the additional 
latency (for non-x86 archs) only matters if the master lock is 
immediately available for acquisition after osq_lock() return. 
Otherwise, it will be hidden in the spinning loop for that master lock. 
So yes, there may be a slight performance hit in some cases, but 
certainly not always.

> If you need tighter osq for rwsems, could it be refactored such that 
> mutexes
> do not take a hit?
>

Yes, we can certainly do that like splitting into 2 variants, one with 
acquire barrier guarantee and one without.

>>
>> Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
>> Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
>> ---
>> kernel/locking/osq_lock.c |   24 ++++++++++++++++++------
>> 1 files changed, 18 insertions(+), 6 deletions(-)
>>
>> diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
>> index 05a3785..3da0b97 100644
>> --- a/kernel/locking/osq_lock.c
>> +++ b/kernel/locking/osq_lock.c
>> @@ -124,6 +124,11 @@ bool osq_lock(struct optimistic_spin_queue *lock)
>>
>>         cpu_relax_lowlatency();
>>     }
>> +    /*
>> +     * Add an acquire memory barrier for pairing with the release 
>> barrier
>> +     * in unlock.
>> +     */
>> +    smp_acquire__after_ctrl_dep();
>>     return true;
>>
>> unqueue:
>> @@ -198,13 +203,20 @@ void osq_unlock(struct optimistic_spin_queue 
>> *lock)
>>      * Second most likely case.
>>      */
>>     node = this_cpu_ptr(&osq_node);
>> -    next = xchg(&node->next, NULL);
>> -    if (next) {
>> -        WRITE_ONCE(next->locked, 1);
>> +    next = xchg_relaxed(&node->next, NULL);
>> +    if (next)
>> +        goto unlock;
>> +
>> +    next = osq_wait_next(lock, node, NULL);
>> +    if (unlikely(!next)) {
>> +        /*
>> +         * In the unlikely event that the OSQ is empty, we need to
>> +         * provide a proper release barrier.
>> +         */
>> +        smp_mb();
>>         return;
>>     }
>>
>> -    next = osq_wait_next(lock, node, NULL);
>> -    if (next)
>> -        WRITE_ONCE(next->locked, 1);
>> +unlock:
>> +    smp_store_release(&next->locked, 1);
>> }
>
> As well as for the smp_acquire__after_ctrl_dep comment you have above, 
> this also
> obviously pairs with the osq_lock's smp_load_acquire while backing out 
> (unqueueing,
> step A). Given the above, for this case we might also just rely on 
> READ_ONCE(node->locked),
> if we get the conditional wrong and miss the node becoming locked, all 
> we do is another
> iteration, and while there is a cmpxchg() there, it is mitigated with 
> the ccas thingy.

Similar to osq_lock(), the current osq_unlock() does not have a release 
barrier guarantee. I think splitting into 2 variants - osq_unlock, 
osq_unlock_relaxed will help.

Cheers,
Longman

Re: [RFC PATCH-tip v4 01/10] locking/osq: Make lock/unlock proper acquire/release barrier

[Waiman Long]

On 10/05/2016 08:19 AM, Waiman Long wrote:
> On 10/04/2016 03:06 PM, Davidlohr Bueso wrote:
>> On Thu, 18 Aug 2016, Waiman Long wrote:
>>
>>> The osq_lock() and osq_unlock() function may not provide the necessary
>>> acquire and release barrier in some cases. This patch makes sure
>>> that the proper barriers are provided when osq_lock() is successful
>>> or when osq_unlock() is called.
>>
>> But why do we need these guarantees given that osq is only used 
>> internally
>> for lock owner spinning situations? Leaking out of the critical 
>> region will
>> obviously be bad if using it as a full lock, but, as is, this can 
>> only hurt
>> performance of two of the most popular locks in the kernel -- 
>> although yes,
>> using smp_acquire__after_ctrl_dep is nicer for polling.
>
> First of all, it is not obvious from the name osq_lock() that it is 
> not an acquire barrier in some cases. We either need to clearly 
> document it or has a variant name that indicate that, e.g. 
> osq_lock_relaxed, for example.
>
> Secondly, if we look at the use cases of osq_lock(), the additional 
> latency (for non-x86 archs) only matters if the master lock is 
> immediately available for acquisition after osq_lock() return. 
> Otherwise, it will be hidden in the spinning loop for that master 
> lock. So yes, there may be a slight performance hit in some cases, but 
> certainly not always.
>
>> If you need tighter osq for rwsems, could it be refactored such that 
>> mutexes
>> do not take a hit?
>>
>
> Yes, we can certainly do that like splitting into 2 variants, one with 
> acquire barrier guarantee and one without.
>

How about the following patch? Does that address your concern?

Cheers,
Longman

----------------------------------[ Cut Here 
]--------------------------------------
[PATCH] locking/osq: Provide 2 variants of lock/unlock functions

Despite the lock/unlock names, the osq_lock() and osq_unlock()
functions were not proper acquire and release barriers. To clarify
the situation, two different variants are now provided:

  1) osq_lock/osq_unlock - they are proper acquire (if successful)
     and release barriers respectively.

  2) osq_lock_relaxed/osq_unlock_relaxed - they do not provide the
     acquire/release barrier guarantee.

Both the mutex and rwsem optimistic spinning codes are modified to
use the relaxed variants which will be faster in some architectures as
the proper memory barrier semantics are not needed for queuing purpose.

Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
---
  include/linux/osq_lock.h    |    2 +
  kernel/locking/mutex.c      |    6 +-
  kernel/locking/osq_lock.c   |   89 
+++++++++++++++++++++++++++++++++++-------
  kernel/locking/rwsem-xadd.c |    4 +-
  4 files changed, 81 insertions(+), 20 deletions(-)

diff --git a/include/linux/osq_lock.h b/include/linux/osq_lock.h
index 703ea5c..72357d0 100644
--- a/include/linux/osq_lock.h
+++ b/include/linux/osq_lock.h
@@ -30,7 +30,9 @@ static inline void osq_lock_init(struct 
optimistic_spin_queue *lock)
  }

  extern bool osq_lock(struct optimistic_spin_queue *lock);
+extern bool osq_lock_relaxed(struct optimistic_spin_queue *lock);
  extern void osq_unlock(struct optimistic_spin_queue *lock);
+extern void osq_unlock_relaxed(struct optimistic_spin_queue *lock);

  static inline bool osq_is_locked(struct optimistic_spin_queue *lock)
  {
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index a70b90d..b1bf1e0 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -316,7 +316,7 @@ static bool mutex_optimistic_spin(struct mutex *lock,
       * acquire the mutex all at once, the spinners need to take a
       * MCS (queued) lock first before spinning on the owner field.
       */
-    if (!osq_lock(&lock->osq))
+    if (!osq_lock_relaxed(&lock->osq))
          goto done;

      while (true) {
@@ -358,7 +358,7 @@ static bool mutex_optimistic_spin(struct mutex *lock,
              }

              mutex_set_owner(lock);
-            osq_unlock(&lock->osq);
+            osq_unlock_relaxed(&lock->osq);
              return true;
          }

@@ -380,7 +380,7 @@ static bool mutex_optimistic_spin(struct mutex *lock,
          cpu_relax_lowlatency();
      }

-    osq_unlock(&lock->osq);
+    osq_unlock_relaxed(&lock->osq);
  done:
      /*
       * If we fell out of the spin path because of need_resched(),
diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
index 05a3785..1e6823a 100644
--- a/kernel/locking/osq_lock.c
+++ b/kernel/locking/osq_lock.c
@@ -12,6 +12,23 @@
   */
  static DEFINE_PER_CPU_SHARED_ALIGNED(struct optimistic_spin_node, 
osq_node);

+enum mbtype {
+    acquire,
+    release,
+    relaxed,
+};
+
+static __always_inline int
+_atomic_cmpxchg_(const enum mbtype barrier, atomic_t *v, int old, int new)
+{
+    if (barrier == acquire)
+        return atomic_cmpxchg_acquire(v, old, new);
+    else if (barrier == release)
+        return atomic_cmpxchg_release(v, old, new);
+    else
+        return atomic_cmpxchg_relaxed(v, old, new);
+}
+
  /*
   * We use the value 0 to represent "no CPU", thus the encoded value
   * will be the CPU number incremented by 1.
@@ -35,7 +52,8 @@ static inline struct optimistic_spin_node 
*decode_cpu(int encoded_cpu_val)
  static inline struct optimistic_spin_node *
  osq_wait_next(struct optimistic_spin_queue *lock,
            struct optimistic_spin_node *node,
-          struct optimistic_spin_node *prev)
+          struct optimistic_spin_node *prev,
+          const enum mbtype barrier)
  {
      struct optimistic_spin_node *next = NULL;
      int curr = encode_cpu(smp_processor_id());
@@ -50,7 +68,7 @@ osq_wait_next(struct optimistic_spin_queue *lock,

      for (;;) {
          if (atomic_read(&lock->tail) == curr &&
-            atomic_cmpxchg_acquire(&lock->tail, curr, old) == curr) {
+           _atomic_cmpxchg_(barrier, &lock->tail, curr, old) == curr) {
              /*
               * We were the last queued, we moved @lock back. @prev
               * will now observe @lock and will complete its
@@ -70,7 +88,13 @@ osq_wait_next(struct optimistic_spin_queue *lock,
           * wait for a new @node->next from its Step-C.
           */
          if (node->next) {
-            next = xchg(&node->next, NULL);
+            if (barrier == acquire)
+                next = xchg_acquire(&node->next, NULL);
+            else if (barrier == release)
+                next = xchg_release(&node->next, NULL);
+            else
+                next = xchg_relaxed(&node->next, NULL);
+
              if (next)
                  break;
          }
@@ -81,7 +105,11 @@ osq_wait_next(struct optimistic_spin_queue *lock,
      return next;
  }

-bool osq_lock(struct optimistic_spin_queue *lock)
+/*
+ * We don't need to provide any memory barrier guarantee if the locking 
fails.
+ */
+static inline bool
+__osq_lock(struct optimistic_spin_queue *lock, const enum mbtype barrier)
  {
      struct optimistic_spin_node *node = this_cpu_ptr(&osq_node);
      struct optimistic_spin_node *prev, *next;
@@ -124,6 +152,12 @@ bool osq_lock(struct optimistic_spin_queue *lock)

          cpu_relax_lowlatency();
      }
+    /*
+     * Add an acquire memory barrier, if necessary, for pairing with the
+     * release barrier in unlock.
+     */
+    if (barrier == acquire)
+        smp_acquire__after_ctrl_dep();
      return true;

  unqueue:
@@ -137,7 +171,7 @@ unqueue:

      for (;;) {
          if (prev->next == node &&
-            cmpxchg(&prev->next, node, NULL) == node)
+            cmpxchg_relaxed(&prev->next, node, NULL) == node)
              break;

          /*
@@ -164,7 +198,7 @@ unqueue:
       * back to @prev.
       */

-    next = osq_wait_next(lock, node, prev);
+    next = osq_wait_next(lock, node, prev, relaxed);
      if (!next)
          return false;

@@ -182,7 +216,8 @@ unqueue:
      return false;
  }

-void osq_unlock(struct optimistic_spin_queue *lock)
+static inline void
+__osq_unlock(struct optimistic_spin_queue *lock, const enum mbtype barrier)
  {
      struct optimistic_spin_node *node, *next;
      int curr = encode_cpu(smp_processor_id());
@@ -190,21 +225,45 @@ void osq_unlock(struct optimistic_spin_queue *lock)
      /*
       * Fast path for the uncontended case.
       */
-    if (likely(atomic_cmpxchg_release(&lock->tail, curr,
-                      OSQ_UNLOCKED_VAL) == curr))
+    if (likely(_atomic_cmpxchg_(barrier, &lock->tail, curr,
+                    OSQ_UNLOCKED_VAL) == curr))
          return;

      /*
       * Second most likely case.
       */
      node = this_cpu_ptr(&osq_node);
-    next = xchg(&node->next, NULL);
-    if (next) {
-        WRITE_ONCE(next->locked, 1);
+    next = xchg_relaxed(&node->next, NULL);
+    if (next)
+        goto unlock;
+
+    next = osq_wait_next(lock, node, NULL, barrier);
+    if (unlikely(!next))
          return;
-    }

-    next = osq_wait_next(lock, node, NULL);
-    if (next)
+unlock:
+    if (barrier == release)
+        smp_store_release(&next->locked, 1);
+    else
          WRITE_ONCE(next->locked, 1);
  }
+
+bool osq_lock(struct optimistic_spin_queue *lock)
+{
+    return __osq_lock(lock, acquire);
+}
+
+bool osq_lock_relaxed(struct optimistic_spin_queue *lock)
+{
+    return __osq_lock(lock, relaxed);
+}
+
+void osq_unlock(struct optimistic_spin_queue *lock)
+{
+    __osq_unlock(lock, release);
+}
+
+void osq_unlock_relaxed(struct optimistic_spin_queue *lock)
+{
+    __osq_unlock(lock, relaxed);
+}
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 2337b4b..88e95b1 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -389,7 +389,7 @@ static bool rwsem_optimistic_spin(struct 
rw_semaphore *sem)
      if (!rwsem_can_spin_on_owner(sem))
          goto done;

-    if (!osq_lock(&sem->osq))
+    if (!osq_lock_relaxed(&sem->osq))
          goto done;

      /*
@@ -425,7 +425,7 @@ static bool rwsem_optimistic_spin(struct 
rw_semaphore *sem)
           */
          cpu_relax_lowlatency();
      }
-    osq_unlock(&sem->osq);
+    osq_unlock_relaxed(&sem->osq);
  done:
      preempt_enable();
      return taken;
-- 
1.7.1

Re: [RFC PATCH-tip v4 01/10] locking/osq: Make lock/unlock proper acquire/release barrier

[Davidlohr Bueso]

On Wed, 05 Oct 2016, Waiman Long wrote:

>diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
>index 05a3785..1e6823a 100644
>--- a/kernel/locking/osq_lock.c
>+++ b/kernel/locking/osq_lock.c
>@@ -12,6 +12,23 @@
>  */
> static DEFINE_PER_CPU_SHARED_ALIGNED(struct optimistic_spin_node, 
>osq_node);
>
>+enum mbtype {
>+    acquire,
>+    release,
>+    relaxed,
>+};

No, please.

>+
>+static __always_inline int
>+_atomic_cmpxchg_(const enum mbtype barrier, atomic_t *v, int old, int new)
>+{
>+    if (barrier == acquire)
>+        return atomic_cmpxchg_acquire(v, old, new);
>+    else if (barrier == release)
>+        return atomic_cmpxchg_release(v, old, new);
>+    else
>+        return atomic_cmpxchg_relaxed(v, old, new);
>+}

Things like the above are icky. How about something like below? I'm not
crazy about it, but there are other similar macros, ie lockref. We still
provide the osq_lock/unlock to imply acquire/release and the new _relaxed
flavor, as I agree that should be the correct naming

While I have not touched osq_wait_next(), the following are impacted:

- node->locked is now completely without ordering for _relaxed() (currently
its under smp_load_acquire, which does not match and the race is harmless
to begin with as we just iterate again. For the acquire flavor, it is always
formed with ctr dep + smp_rmb().

- If osq_lock() fails we never guarantee any ordering.

What do you think?

Thanks,
Davidlohr


diff --git a/include/linux/osq_lock.h b/include/linux/osq_lock.h
index 703ea5c30a33..183ee51e6e54 100644
--- a/include/linux/osq_lock.h
+++ b/include/linux/osq_lock.h
@@ -29,9 +29,20 @@ static inline void osq_lock_init(struct optimistic_spin_queue *lock)
 	atomic_set(&lock->tail, OSQ_UNLOCKED_VAL);
 }
 
+/*
+ * Versions of osq_lock/unlock that do not imply or guarantee (load)-ACQUIRE
+ * (store)-RELEASE barrier semantics.
+ *
+ * Note that a failed call to either osq_lock() or osq_lock_relaxed() does
+ * not imply barriers... we are next to block.
+ */
+extern bool osq_lock_relaxed(struct optimistic_spin_queue *lock);
+extern void osq_unlock_relaxed(struct optimistic_spin_queue *lock);
+
 extern bool osq_lock(struct optimistic_spin_queue *lock);
 extern void osq_unlock(struct optimistic_spin_queue *lock);
 
+
 static inline bool osq_is_locked(struct optimistic_spin_queue *lock)
 {
 	return atomic_read(&lock->tail) != OSQ_UNLOCKED_VAL;
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index a70b90db3909..b1bf1e057565 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -316,7 +316,7 @@ static bool mutex_optimistic_spin(struct mutex *lock,
 	 * acquire the mutex all at once, the spinners need to take a
 	 * MCS (queued) lock first before spinning on the owner field.
 	 */
-	if (!osq_lock(&lock->osq))
+	if (!osq_lock_relaxed(&lock->osq))
 		goto done;
 
 	while (true) {
@@ -358,7 +358,7 @@ static bool mutex_optimistic_spin(struct mutex *lock,
 			}
 
 			mutex_set_owner(lock);
-			osq_unlock(&lock->osq);
+			osq_unlock_relaxed(&lock->osq);
 			return true;
 		}
 
@@ -380,7 +380,7 @@ static bool mutex_optimistic_spin(struct mutex *lock,
 		cpu_relax_lowlatency();
 	}
 
-	osq_unlock(&lock->osq);
+	osq_unlock_relaxed(&lock->osq);
 done:
 	/*
 	 * If we fell out of the spin path because of need_resched(),
diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
index 05a37857ab55..8c3d57698702 100644
--- a/kernel/locking/osq_lock.c
+++ b/kernel/locking/osq_lock.c
@@ -28,6 +28,17 @@ static inline struct optimistic_spin_node *decode_cpu(int encoded_cpu_val)
 	return per_cpu_ptr(&osq_node, cpu_nr);
 }
 
+static inline void set_node_locked_release(struct optimistic_spin_node *node)
+{
+	smp_store_release(&node->locked, 1);
+}
+
+static inline void set_node_locked_relaxed(struct optimistic_spin_node *node)
+{
+	WRITE_ONCE(node->locked, 1);
+
+}
+
 /*
  * Get a stable @node->next pointer, either for unlock() or unqueue() purposes.
  * Can return NULL in case we were the last queued and we updated @lock instead.
@@ -81,130 +92,140 @@ osq_wait_next(struct optimistic_spin_queue *lock,
 	return next;
 }
 
-bool osq_lock(struct optimistic_spin_queue *lock)
-{
-	struct optimistic_spin_node *node = this_cpu_ptr(&osq_node);
-	struct optimistic_spin_node *prev, *next;
-	int curr = encode_cpu(smp_processor_id());
-	int old;
-
-	node->locked = 0;
-	node->next = NULL;
-	node->cpu = curr;
-
-	/*
-	 * We need both ACQUIRE (pairs with corresponding RELEASE in
-	 * unlock() uncontended, or fastpath) and RELEASE (to publish
-	 * the node fields we just initialised) semantics when updating
-	 * the lock tail.
-	 */
-	old = atomic_xchg(&lock->tail, curr);
-	if (old == OSQ_UNLOCKED_VAL)
-		return true;
-
-	prev = decode_cpu(old);
-	node->prev = prev;
-	WRITE_ONCE(prev->next, node);
-
-	/*
-	 * Normally @prev is untouchable after the above store; because at that
-	 * moment unlock can proceed and wipe the node element from stack.
-	 *
-	 * However, since our nodes are static per-cpu storage, we're
-	 * guaranteed their existence -- this allows us to apply
-	 * cmpxchg in an attempt to undo our queueing.
-	 */
-
-	while (!READ_ONCE(node->locked)) {
-		/*
-		 * If we need to reschedule bail... so we can block.
-		 */
-		if (need_resched())
-			goto unqueue;
-
-		cpu_relax_lowlatency();
-	}
-	return true;
-
-unqueue:
-	/*
-	 * Step - A  -- stabilize @prev
-	 *
-	 * Undo our @prev->next assignment; this will make @prev's
-	 * unlock()/unqueue() wait for a next pointer since @lock points to us
-	 * (or later).
-	 */
-
-	for (;;) {
-		if (prev->next == node &&
-		    cmpxchg(&prev->next, node, NULL) == node)
-			break;
-
-		/*
-		 * We can only fail the cmpxchg() racing against an unlock(),
-		 * in which case we should observe @node->locked becomming
-		 * true.
-		 */
-		if (smp_load_acquire(&node->locked))
-			return true;
-
-		cpu_relax_lowlatency();
-
-		/*
-		 * Or we race against a concurrent unqueue()'s step-B, in which
-		 * case its step-C will write us a new @node->prev pointer.
-		 */
-		prev = READ_ONCE(node->prev);
-	}
-
-	/*
-	 * Step - B -- stabilize @next
-	 *
-	 * Similar to unlock(), wait for @node->next or move @lock from @node
-	 * back to @prev.
-	 */
-
-	next = osq_wait_next(lock, node, prev);
-	if (!next)
-		return false;
-
-	/*
-	 * Step - C -- unlink
-	 *
-	 * @prev is stable because its still waiting for a new @prev->next
-	 * pointer, @next is stable because our @node->next pointer is NULL and
-	 * it will wait in Step-A.
-	 */
-
-	WRITE_ONCE(next->prev, prev);
-	WRITE_ONCE(prev->next, next);
-
-	return false;
+#define OSQ_LOCK(EXT, FENCECB)						\
+bool osq_lock##EXT(struct optimistic_spin_queue *lock)			\
+{									\
+	struct optimistic_spin_node *node = this_cpu_ptr(&osq_node);	\
+	struct optimistic_spin_node *prev, *next;			\
+	int old, curr = encode_cpu(smp_processor_id());			\
+									\
+	node->locked = 0;						\
+	node->next = NULL;						\
+	node->cpu = curr;						\
+									\
+	/*								\
+	 * We need both ACQUIRE (pairs with corresponding RELEASE in	\
+	 * unlock() uncontended, or fastpath) and RELEASE (to publish	\
+	 * the node fields we just initialised) semantics when updating \
+	 * the lock tail.						\
+	 */								\
+	old = atomic_xchg(&lock->tail, curr);				\
+	if (old == OSQ_UNLOCKED_VAL)					\
+		return true;						\
+									\
+	prev = decode_cpu(old);						\
+	node->prev = prev;						\
+	WRITE_ONCE(prev->next, node);					\
+									\
+	/*								\
+	 * Normally @prev is untouchable after the above store; because \
+	 * at that moment unlock can proceed and wipe the node element  \
+	 * from stack.							\
+	 *								\
+	 * However, since our nodes are static per-cpu storage, we're   \
+	 * guaranteed their existence -- this allows us to apply	\
+	 * cmpxchg in an attempt to undo our queueing.			\
+	 */								\
+	while (!READ_ONCE(node->locked)) {				\
+		/*							\
+		 * If we need to reschedule bail... so we can block.	\
+		 */							\
+		if (need_resched())					\
+			goto unqueue;					\
+									\
+		cpu_relax_lowlatency();					\
+	}								\
+	FENCECB;							\
+	return true;							\
+									\
+unqueue:								\
+	/*								\
+	 * Step - A  -- stabilize @prev					\
+	 *								\
+	 * Undo our @prev->next assignment; this will make @prev's      \
+	 * unlock()/unqueue() wait for a next pointer since @lock	\
+	 * points to us (or later).					\
+	 */								\
+	for (;;) {							\
+		/*							\
+		 * Failed calls to osq_lock() do not guarantee		\
+		 * barriers, thus always rely on RELAXED semantics.	\
+		 */							\
+		if (prev->next == node &&				\
+		    cmpxchg_relaxed(&prev->next, node, NULL) == node)	\
+			break;						\
+									\
+		/*							\
+		 * We can only fail the cmpxchg() racing against an	\
+		 * unlock(), in which case we should observe		\
+		 * @node->locked becoming true.				\
+		 */							\
+		if (READ_ONCE(node->locked)) {				\
+			FENCECB;					\
+			return true;					\
+		}							\
+									\
+		cpu_relax_lowlatency();					\
+									\
+		/*							\
+		 * Or we race against a concurrent unqueue()'s step-B,  \
+		 * in which  case its step-C will write us a new	\
+		 * @node->prev pointer.					\
+		 */							\
+		prev = READ_ONCE(node->prev);				\
+	}								\
+									\
+	/*								\
+	 * Step - B -- stabilize @next					\
+	 *								\
+	 * Similar to unlock(), wait for @node->next or move @lock	\
+	 * from @node back to @prev.					\
+	 */								\
+									\
+	next = osq_wait_next(lock, node, prev);				\
+	if (!next)							\
+		return false;						\
+									\
+	/*								\
+	 * Step - C -- unlink						\
+	 *								\
+	 * @prev is stable because its still waiting for a new		\
+	 * @prev->next pointer, @next is stable because our		\
+	 * @node->next pointer is NULL and it will wait in Step-A.	\
+	 */								\
+									\
+	WRITE_ONCE(next->prev, prev);					\
+	WRITE_ONCE(prev->next, next);					\
+									\
+	return false;							\
 }
 
-void osq_unlock(struct optimistic_spin_queue *lock)
-{
-	struct optimistic_spin_node *node, *next;
-	int curr = encode_cpu(smp_processor_id());
-
-	/*
-	 * Fast path for the uncontended case.
-	 */
-	if (likely(atomic_cmpxchg_release(&lock->tail, curr,
-					  OSQ_UNLOCKED_VAL) == curr))
-		return;
-
-	/*
-	 * Second most likely case.
-	 */
-	node = this_cpu_ptr(&osq_node);
-	next = xchg(&node->next, NULL);
-	if (next) {
-		WRITE_ONCE(next->locked, 1);
-		return;
-	}
-
-	next = osq_wait_next(lock, node, NULL);
-	if (next)
-		WRITE_ONCE(next->locked, 1);
+OSQ_LOCK(, smp_acquire__after_ctrl_dep())
+OSQ_LOCK(_relaxed, )
+
+#define OSQ_UNLOCK(EXT, FENCE)						\
+void osq_unlock##EXT(struct optimistic_spin_queue *lock)                \
+{									\
+	struct optimistic_spin_node *node, *next;			\
+	int curr = encode_cpu(smp_processor_id());			\
+									\
+	/* Fast path for the uncontended case. */			\
+	if (likely(atomic_cmpxchg_##FENCE(&lock->tail, curr,		\
+					  OSQ_UNLOCKED_VAL) == curr))	\
+		return;							\
+									\
+	/* Second most likely case. */					\
+	node = this_cpu_ptr(&osq_node);					\
+	next = xchg(&node->next, NULL);					\
+	if (next)							\
+		goto done_setlocked;					\
+									\
+	next = osq_wait_next(lock, node, NULL);				\
+	if (!next)							\
+		return;							\
+done_setlocked:								\
+	set_node_locked_##FENCE(next);					\
 }
+
+OSQ_UNLOCK(, release)
+OSQ_UNLOCK(_relaxed, relaxed)
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 2337b4bb2366..88e95b114392 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -389,7 +389,7 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
 	if (!rwsem_can_spin_on_owner(sem))
 		goto done;
 
-	if (!osq_lock(&sem->osq))
+	if (!osq_lock_relaxed(&sem->osq))
 		goto done;
 
 	/*
@@ -425,7 +425,7 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
 		 */
 		cpu_relax_lowlatency();
 	}
-	osq_unlock(&sem->osq);
+	osq_unlock_relaxed(&sem->osq);
 done:
 	preempt_enable();
 	return taken;

Re: [RFC PATCH-tip v4 01/10] locking/osq: Make lock/unlock proper acquire/release barrier

[Waiman Long]

On 10/06/2016 01:47 AM, Davidlohr Bueso wrote:
> On Wed, 05 Oct 2016, Waiman Long wrote:
>
>> diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
>> index 05a3785..1e6823a 100644
>> --- a/kernel/locking/osq_lock.c
>> +++ b/kernel/locking/osq_lock.c
>> @@ -12,6 +12,23 @@
>>  */
>> static DEFINE_PER_CPU_SHARED_ALIGNED(struct optimistic_spin_node, 
>> osq_node);
>>
>> +enum mbtype {
>> +    acquire,
>> +    release,
>> +    relaxed,
>> +};
>
> No, please.
>
>> +
>> +static __always_inline int
>> +_atomic_cmpxchg_(const enum mbtype barrier, atomic_t *v, int old, 
>> int new)
>> +{
>> +    if (barrier == acquire)
>> +        return atomic_cmpxchg_acquire(v, old, new);
>> +    else if (barrier == release)
>> +        return atomic_cmpxchg_release(v, old, new);
>> +    else
>> +        return atomic_cmpxchg_relaxed(v, old, new);
>> +}
>
> Things like the above are icky. How about something like below? I'm not
> crazy about it, but there are other similar macros, ie lockref. We still
> provide the osq_lock/unlock to imply acquire/release and the new _relaxed
> flavor, as I agree that should be the correct naming
>
> While I have not touched osq_wait_next(), the following are impacted:
>
> - node->locked is now completely without ordering for _relaxed() 
> (currently
> its under smp_load_acquire, which does not match and the race is harmless
> to begin with as we just iterate again. For the acquire flavor, it is 
> always
> formed with ctr dep + smp_rmb().
>
> - If osq_lock() fails we never guarantee any ordering.
>
> What do you think?
>
> Thanks,
> Davidlohr

Yes, I am OK with your change. However, I need some additional changes 
in osq_wait_next() as well. Either it is changed to use the release 
variants of atomic_cmpxchg and xchg or using macro like what you did 
with osq_lock and osq_unlock. The release variant is needed in the 
osq_lock(). As osq_wait_next() is only invoked in the failure path of 
osq_lock(), the barrier type doesn't really matter.

Cheers,
Longman

[PATCH] locking/osq: Provide proper lock/unlock and relaxed flavors

[Davidlohr Bueso]

Because osq has only been used for mutex/rwsem spinning logic,
we have gotten away with being rather flexible in any of the
traditional lock/unlock ACQUIRE/RELEASE minimal guarantees.
However, if wanted to be used as a _real_ lock, then it would
be in trouble. To this end, this patch provides the two
alternatives, where osq_lock/unlock() calls have the required
semantics, and a _relaxed() call, for no ordering guarantees
at all.

- node->locked is now completely without ordering for _relaxed()
(currently its under smp_load_acquire, which does not match and
the race is harmless to begin with as we just iterate again. For
the ACQUIRE flavor, it is always formed with ctr dep + smp_rmb().

- In order to avoid more code duplication via macros, the common
osq_wait_next() call is completely unordered, but the caller
can provide the necessary barriers, if required - ie the case for
osq_unlock(): similar to the node->locked case, this also relies
on ctrl dep + smp_wmb() to form RELEASE.

- If osq_lock() fails we never guarantee any ordering (obviously
same goes for _relaxed).

Both mutexes and rwsems have been updated to continue using the
relaxed versions, but this will obviously change for the later.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
XXX: This obviously needs a lot of testing.

 include/asm-generic/barrier.h |   9 ++
 include/linux/osq_lock.h      |  10 ++
 kernel/locking/mutex.c        |   6 +-
 kernel/locking/osq_lock.c     | 279 +++++++++++++++++++++++-------------------
 kernel/locking/rwsem-xadd.c   |   4 +-
 5 files changed, 177 insertions(+), 131 deletions(-)

diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h
index fe297b599b0a..0036b08151c3 100644
--- a/include/asm-generic/barrier.h
+++ b/include/asm-generic/barrier.h
@@ -221,6 +221,15 @@ do {									\
 #endif
 
 /**
+ * smp_release__after_ctrl_dep() - Provide RELEASE ordering after a control dependency
+ *
+ * A control dependency provides a LOAD->STORE order, the additional WMB
+ * provides STORE->STORE order, together they provide {LOAD,STORE}->STORE order,
+ * aka. (store)-RELEASE.
+ */
+#define smp_release__after_ctrl_dep()		smp_wmb()
+
+/**
  * smp_cond_load_acquire() - (Spin) wait for cond with ACQUIRE ordering
  * @ptr: pointer to the variable to wait on
  * @cond: boolean expression to wait for
diff --git a/include/linux/osq_lock.h b/include/linux/osq_lock.h
index 703ea5c30a33..a63ffa95aa70 100644
--- a/include/linux/osq_lock.h
+++ b/include/linux/osq_lock.h
@@ -29,6 +29,16 @@ static inline void osq_lock_init(struct optimistic_spin_queue *lock)
 	atomic_set(&lock->tail, OSQ_UNLOCKED_VAL);
 }
 
+/*
+ * Versions of osq_lock/unlock that do not imply or guarantee (load)-ACQUIRE
+ * (store)-RELEASE barrier semantics.
+ *
+ * Note that a failed call to either osq_lock() or osq_lock_relaxed() does
+ * not imply barriers... we are next to block.
+ */
+extern bool osq_lock_relaxed(struct optimistic_spin_queue *lock);
+extern void osq_unlock_relaxed(struct optimistic_spin_queue *lock);
+
 extern bool osq_lock(struct optimistic_spin_queue *lock);
 extern void osq_unlock(struct optimistic_spin_queue *lock);
 
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index a70b90db3909..b1bf1e057565 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -316,7 +316,7 @@ static bool mutex_optimistic_spin(struct mutex *lock,
 	 * acquire the mutex all at once, the spinners need to take a
 	 * MCS (queued) lock first before spinning on the owner field.
 	 */
-	if (!osq_lock(&lock->osq))
+	if (!osq_lock_relaxed(&lock->osq))
 		goto done;
 
 	while (true) {
@@ -358,7 +358,7 @@ static bool mutex_optimistic_spin(struct mutex *lock,
 			}
 
 			mutex_set_owner(lock);
-			osq_unlock(&lock->osq);
+			osq_unlock_relaxed(&lock->osq);
 			return true;
 		}
 
@@ -380,7 +380,7 @@ static bool mutex_optimistic_spin(struct mutex *lock,
 		cpu_relax_lowlatency();
 	}
 
-	osq_unlock(&lock->osq);
+	osq_unlock_relaxed(&lock->osq);
 done:
 	/*
 	 * If we fell out of the spin path because of need_resched(),
diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
index 05a37857ab55..d3d1042a509c 100644
--- a/kernel/locking/osq_lock.c
+++ b/kernel/locking/osq_lock.c
@@ -28,6 +28,17 @@ static inline struct optimistic_spin_node *decode_cpu(int encoded_cpu_val)
 	return per_cpu_ptr(&osq_node, cpu_nr);
 }
 
+static inline void set_node_locked_release(struct optimistic_spin_node *node)
+{
+	smp_store_release(&node->locked, 1);
+}
+
+static inline void set_node_locked_relaxed(struct optimistic_spin_node *node)
+{
+	WRITE_ONCE(node->locked, 1);
+
+}
+
 /*
  * Get a stable @node->next pointer, either for unlock() or unqueue() purposes.
  * Can return NULL in case we were the last queued and we updated @lock instead.
@@ -50,7 +61,7 @@ osq_wait_next(struct optimistic_spin_queue *lock,
 
 	for (;;) {
 		if (atomic_read(&lock->tail) == curr &&
-		    atomic_cmpxchg_acquire(&lock->tail, curr, old) == curr) {
+		    atomic_cmpxchg_relaxed(&lock->tail, curr, old) == curr) {
 			/*
 			 * We were the last queued, we moved @lock back. @prev
 			 * will now observe @lock and will complete its
@@ -70,7 +81,7 @@ osq_wait_next(struct optimistic_spin_queue *lock,
 		 * wait for a new @node->next from its Step-C.
 		 */
 		if (node->next) {
-			next = xchg(&node->next, NULL);
+			next = xchg_relaxed(&node->next, NULL);
 			if (next)
 				break;
 		}
@@ -81,130 +92,146 @@ osq_wait_next(struct optimistic_spin_queue *lock,
 	return next;
 }
 
-bool osq_lock(struct optimistic_spin_queue *lock)
-{
-	struct optimistic_spin_node *node = this_cpu_ptr(&osq_node);
-	struct optimistic_spin_node *prev, *next;
-	int curr = encode_cpu(smp_processor_id());
-	int old;
-
-	node->locked = 0;
-	node->next = NULL;
-	node->cpu = curr;
-
-	/*
-	 * We need both ACQUIRE (pairs with corresponding RELEASE in
-	 * unlock() uncontended, or fastpath) and RELEASE (to publish
-	 * the node fields we just initialised) semantics when updating
-	 * the lock tail.
-	 */
-	old = atomic_xchg(&lock->tail, curr);
-	if (old == OSQ_UNLOCKED_VAL)
-		return true;
-
-	prev = decode_cpu(old);
-	node->prev = prev;
-	WRITE_ONCE(prev->next, node);
-
-	/*
-	 * Normally @prev is untouchable after the above store; because at that
-	 * moment unlock can proceed and wipe the node element from stack.
-	 *
-	 * However, since our nodes are static per-cpu storage, we're
-	 * guaranteed their existence -- this allows us to apply
-	 * cmpxchg in an attempt to undo our queueing.
-	 */
-
-	while (!READ_ONCE(node->locked)) {
-		/*
-		 * If we need to reschedule bail... so we can block.
-		 */
-		if (need_resched())
-			goto unqueue;
-
-		cpu_relax_lowlatency();
-	}
-	return true;
-
-unqueue:
-	/*
-	 * Step - A  -- stabilize @prev
-	 *
-	 * Undo our @prev->next assignment; this will make @prev's
-	 * unlock()/unqueue() wait for a next pointer since @lock points to us
-	 * (or later).
-	 */
-
-	for (;;) {
-		if (prev->next == node &&
-		    cmpxchg(&prev->next, node, NULL) == node)
-			break;
-
-		/*
-		 * We can only fail the cmpxchg() racing against an unlock(),
-		 * in which case we should observe @node->locked becomming
-		 * true.
-		 */
-		if (smp_load_acquire(&node->locked))
-			return true;
-
-		cpu_relax_lowlatency();
-
-		/*
-		 * Or we race against a concurrent unqueue()'s step-B, in which
-		 * case its step-C will write us a new @node->prev pointer.
-		 */
-		prev = READ_ONCE(node->prev);
-	}
-
-	/*
-	 * Step - B -- stabilize @next
-	 *
-	 * Similar to unlock(), wait for @node->next or move @lock from @node
-	 * back to @prev.
-	 */
-
-	next = osq_wait_next(lock, node, prev);
-	if (!next)
-		return false;
-
-	/*
-	 * Step - C -- unlink
-	 *
-	 * @prev is stable because its still waiting for a new @prev->next
-	 * pointer, @next is stable because our @node->next pointer is NULL and
-	 * it will wait in Step-A.
-	 */
-
-	WRITE_ONCE(next->prev, prev);
-	WRITE_ONCE(prev->next, next);
-
-	return false;
+#define OSQ_LOCK(EXT, FENCECB)						\
+bool osq_lock##EXT(struct optimistic_spin_queue *lock)			\
+{									\
+	struct optimistic_spin_node *node = this_cpu_ptr(&osq_node);	\
+	struct optimistic_spin_node *prev, *next;			\
+	int old, curr = encode_cpu(smp_processor_id());			\
+									\
+	node->locked = 0;						\
+	node->next = NULL;						\
+	node->cpu = curr;						\
+									\
+	/*								\
+	 * At the very least we need RELEASE semantics to initialize	\
+	 * the node fields _before_ publishing it to the the lock tail.	\
+	 */								\
+	old = atomic_xchg_release(&lock->tail, curr);			\
+	if (old == OSQ_UNLOCKED_VAL) {					\
+		FENCECB;						\
+		return true;						\
+	}								\
+									\
+	prev = decode_cpu(old);						\
+	node->prev = prev;						\
+	WRITE_ONCE(prev->next, node);					\
+									\
+	/*								\
+	 * Normally @prev is untouchable after the above store; because \
+	 * at that moment unlock can proceed and wipe the node element  \
+	 * from stack.							\
+	 *								\
+	 * However, since our nodes are static per-cpu storage, we're   \
+	 * guaranteed their existence -- this allows us to apply	\
+	 * cmpxchg in an attempt to undo our queueing.			\
+	 */								\
+	while (!READ_ONCE(node->locked)) {				\
+		/*							\
+		 * If we need to reschedule bail... so we can block.	\
+		 */							\
+		if (need_resched())					\
+			goto unqueue;					\
+									\
+		cpu_relax_lowlatency();					\
+	}								\
+	FENCECB;							\
+	return true;							\
+									\
+unqueue:								\
+	/*								\
+	 * Step - A  -- stabilize @prev					\
+	 *								\
+	 * Undo our @prev->next assignment; this will make @prev's      \
+	 * unlock()/unqueue() wait for a next pointer since @lock	\
+	 * points to us (or later).					\
+	 */								\
+	for (;;) {							\
+		/*							\
+		 * Failed calls to osq_lock() do not guarantee any	\
+		 * ordering, thus always rely on RELAXED semantics.	\
+		 * This also applies below, in Step - B.		\
+		 */							\
+		if (prev->next == node &&				\
+		    cmpxchg_relaxed(&prev->next, node, NULL) == node)	\
+			break;						\
+									\
+		/*							\
+		 * We can only fail the cmpxchg() racing against an	\
+		 * unlock(), in which case we should observe		\
+		 * @node->locked becoming true.				\
+		 */							\
+		if (READ_ONCE(node->locked)) {				\
+			FENCECB;					\
+			return true;					\
+		}							\
+									\
+		cpu_relax_lowlatency();					\
+									\
+		/*							\
+		 * Or we race against a concurrent unqueue()'s step-B,  \
+		 * in which  case its step-C will write us a new	\
+		 * @node->prev pointer.					\
+		 */							\
+		prev = READ_ONCE(node->prev);				\
+	}								\
+									\
+	/*								\
+	 * Step - B -- stabilize @next					\
+	 *								\
+	 * Similar to unlock(), wait for @node->next or move @lock	\
+	 * from @node back to @prev.					\
+	 */								\
+	next = osq_wait_next(lock, node, prev);				\
+	if (!next)							\
+		return false;						\
+									\
+	/*								\
+	 * Step - C -- unlink						\
+	 *								\
+	 * @prev is stable because its still waiting for a new		\
+	 * @prev->next pointer, @next is stable because our		\
+	 * @node->next pointer is NULL and it will wait in Step-A.	\
+	 */								\
+	WRITE_ONCE(next->prev, prev);					\
+	WRITE_ONCE(prev->next, next);					\
+									\
+	return false;							\
 }
 
-void osq_unlock(struct optimistic_spin_queue *lock)
-{
-	struct optimistic_spin_node *node, *next;
-	int curr = encode_cpu(smp_processor_id());
-
-	/*
-	 * Fast path for the uncontended case.
-	 */
-	if (likely(atomic_cmpxchg_release(&lock->tail, curr,
-					  OSQ_UNLOCKED_VAL) == curr))
-		return;
-
-	/*
-	 * Second most likely case.
-	 */
-	node = this_cpu_ptr(&osq_node);
-	next = xchg(&node->next, NULL);
-	if (next) {
-		WRITE_ONCE(next->locked, 1);
-		return;
-	}
-
-	next = osq_wait_next(lock, node, NULL);
-	if (next)
-		WRITE_ONCE(next->locked, 1);
+OSQ_LOCK(, smp_acquire__after_ctrl_dep())
+OSQ_LOCK(_relaxed, )
+
+#define OSQ_UNLOCK(EXT, FENCE, FENCECB)					\
+void osq_unlock##EXT(struct optimistic_spin_queue *lock)                \
+{									\
+	struct optimistic_spin_node *node, *next;			\
+	int curr = encode_cpu(smp_processor_id());			\
+									\
+	/*								\
+	 * Fast path for the uncontended case.				\
+	 */								\
+	if (likely(atomic_cmpxchg_##FENCE(&lock->tail, curr,		\
+					  OSQ_UNLOCKED_VAL) == curr))	\
+		return;							\
+									\
+	/*								\
+	 * Second most likely case.					\
+	 */								\
+	node = this_cpu_ptr(&osq_node);					\
+	next = xchg(&node->next, NULL);					\
+	if (next)							\
+		goto done_setlocked;					\
+									\
+	next = osq_wait_next(lock, node, NULL);				\
+	if (!next) {							\
+		FENCECB;						\
+		return;							\
+	}								\
+									\
+done_setlocked:								\
+	set_node_locked_##FENCE(next);					\
 }
+
+OSQ_UNLOCK(, release, smp_release__after_ctrl_dep())
+OSQ_UNLOCK(_relaxed, relaxed, )
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 2337b4bb2366..88e95b114392 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -389,7 +389,7 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
 	if (!rwsem_can_spin_on_owner(sem))
 		goto done;
 
-	if (!osq_lock(&sem->osq))
+	if (!osq_lock_relaxed(&sem->osq))
 		goto done;
 
 	/*
@@ -425,7 +425,7 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
 		 */
 		cpu_relax_lowlatency();
 	}
-	osq_unlock(&sem->osq);
+	osq_unlock_relaxed(&sem->osq);
 done:
 	preempt_enable();
 	return taken;
-- 
2.6.6

Re: [RFC PATCH-tip v4 01/10] locking/osq: Make lock/unlock proper acquire/release barrier

[Jason Low]

On Wed, Oct 5, 2016 at 10:47 PM, Davidlohr Bueso <dave@stgolabs.net> wrote:
> On Wed, 05 Oct 2016, Waiman Long wrote:
>
>> diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
>> index 05a3785..1e6823a 100644
>> --- a/kernel/locking/osq_lock.c
>> +++ b/kernel/locking/osq_lock.c
>> @@ -12,6 +12,23 @@
>>  */
>> static DEFINE_PER_CPU_SHARED_ALIGNED(struct optimistic_spin_node,
>> osq_node);
>>
>> +enum mbtype {
>> +    acquire,
>> +    release,
>> +    relaxed,
>> +};
>
>
> No, please.
>
>> +
>> +static __always_inline int
>> +_atomic_cmpxchg_(const enum mbtype barrier, atomic_t *v, int old, int
>> new)
>> +{
>> +    if (barrier == acquire)
>> +        return atomic_cmpxchg_acquire(v, old, new);
>> +    else if (barrier == release)
>> +        return atomic_cmpxchg_release(v, old, new);
>> +    else
>> +        return atomic_cmpxchg_relaxed(v, old, new);
>> +}
>
>
> Things like the above are icky. How about something like below? I'm not
> crazy about it, but there are other similar macros, ie lockref. We still
> provide the osq_lock/unlock to imply acquire/release and the new _relaxed
> flavor, as I agree that should be the correct naming
>
> While I have not touched osq_wait_next(), the following are impacted:
>
> - node->locked is now completely without ordering for _relaxed() (currently
> its under smp_load_acquire, which does not match and the race is harmless
> to begin with as we just iterate again. For the acquire flavor, it is always
> formed with ctr dep + smp_rmb().
>
> - If osq_lock() fails we never guarantee any ordering.
>
> What do you think?

I think that this method looks cleaner than the version with the
conditionals and enum.

My first preference though would be to document that the current code
doesn't provide the acquire semantics. The thinking is that if OSQ is
just used internally as a queuing mechanism and isn't used as a
traditional lock guarding critical sections, then it may just be
misleading and just adds more complexity.

If we do want a separate acquire and relaxed variants, then I think
David's version using macros is a bit more in line with other locking
code.

Jason

[RFC PATCH-tip v4 02/10] locking/rwsem: Stop active read lock ASAP

[Waiman Long]

Currently, when down_read() fails, the active read locking isn't undone
until the rwsem_down_read_failed() function grabs the wait_lock. If the
wait_lock is contended, it may takes a while to get the lock. During
that period, writer lock stealing will be disabled because of the
active read lock.

This patch will release the active read lock ASAP so that writer lock
stealing can happen sooner. The only downside is when the reader is
the first one in the wait queue as it has to issue another atomic
operation to update the count.

On a 4-socket Haswell machine running on a 4.7-rc1 tip-based kernel,
the fio test with multithreaded randrw and randwrite tests on the
same file on a XFS partition on top of a NVDIMM with DAX were run,
the aggregated bandwidths before and after the patch were as follows:

  Test      BW before patch     BW after patch  % change
  ----      ---------------     --------------  --------
  randrw        1210 MB/s          1352 MB/s      +12%
  randwrite     1622 MB/s          1710 MB/s      +5.4%

The write-only microbench also showed improvement because some read
locking was done by the XFS code.

Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
---
 kernel/locking/rwsem-xadd.c |   21 +++++++++++++++------
 1 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 2337b4b..9309e72 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -222,21 +222,31 @@ static void __rwsem_mark_wake(struct rw_semaphore *sem,
 __visible
 struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem)
 {
-	long count, adjustment = -RWSEM_ACTIVE_READ_BIAS;
+	long count, adjustment = 0;
 	struct rwsem_waiter waiter;
 	struct task_struct *tsk = current;
 	WAKE_Q(wake_q);
 
+	/*
+	 * Undo read bias from down_read operation to stop active locking.
+	 * Doing that after taking the wait_lock may block writer lock
+	 * stealing for too long impacting system performance.
+	 */
+	atomic_long_add(-RWSEM_ACTIVE_READ_BIAS, &sem->count);
+
 	waiter.task = tsk;
 	waiter.type = RWSEM_WAITING_FOR_READ;
 
 	raw_spin_lock_irq(&sem->wait_lock);
 	if (list_empty(&sem->wait_list))
-		adjustment += RWSEM_WAITING_BIAS;
+		adjustment = RWSEM_WAITING_BIAS;
 	list_add_tail(&waiter.list, &sem->wait_list);
 
-	/* we're now waiting on the lock, but no longer actively locking */
-	count = atomic_long_add_return(adjustment, &sem->count);
+	/* we're now waiting on the lock */
+	if (adjustment)
+		count = atomic_long_add_return(adjustment, &sem->count);
+	else
+		count = atomic_long_read(&sem->count);
 
 	/*
 	 * If there are no active locks, wake the front queued process(es).
@@ -245,8 +255,7 @@ struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem)
 	 * wake our own waiter to join the existing active readers !
 	 */
 	if (count == RWSEM_WAITING_BIAS ||
-	    (count > RWSEM_WAITING_BIAS &&
-	     adjustment != -RWSEM_ACTIVE_READ_BIAS))
+	    (count > RWSEM_WAITING_BIAS && adjustment))
 		__rwsem_mark_wake(sem, RWSEM_WAKE_ANY, &wake_q);
 
 	raw_spin_unlock_irq(&sem->wait_lock);
-- 
1.7.1

Re: [RFC PATCH-tip v4 02/10] locking/rwsem: Stop active read lock ASAP

[Davidlohr Bueso]

On Thu, 18 Aug 2016, Waiman Long wrote:

>Currently, when down_read() fails, the active read locking isn't undone
>until the rwsem_down_read_failed() function grabs the wait_lock. If the
>wait_lock is contended, it may takes a while to get the lock. During
>that period, writer lock stealing will be disabled because of the
>active read lock.
>
>This patch will release the active read lock ASAP so that writer lock
>stealing can happen sooner. The only downside is when the reader is
>the first one in the wait queue as it has to issue another atomic
>operation to update the count.
>
>On a 4-socket Haswell machine running on a 4.7-rc1 tip-based kernel,
>the fio test with multithreaded randrw and randwrite tests on the
>same file on a XFS partition on top of a NVDIMM with DAX were run,
>the aggregated bandwidths before and after the patch were as follows:
>
>  Test      BW before patch     BW after patch  % change
>  ----      ---------------     --------------  --------
>  randrw        1210 MB/s          1352 MB/s      +12%
>  randwrite     1622 MB/s          1710 MB/s      +5.4%

Yeah, this is really a bad workload to make decisions on locking
heuristics imo - if I'm thinking of the same workload. Mainly because
concurrent buffered io to the same file isn't very realistic and you
end up pathologically pounding on i_rwsem (which used to be until
recently i_mutex until Al's parallel lookup/readdir). Obviously write
lock stealing wins in this case.

Thanks,
Davidlohr

Re: [RFC PATCH-tip v4 02/10] locking/rwsem: Stop active read lock ASAP

[Dave Chinner]

On Thu, Oct 06, 2016 at 11:17:18AM -0700, Davidlohr Bueso wrote:
> On Thu, 18 Aug 2016, Waiman Long wrote:
> 
> >Currently, when down_read() fails, the active read locking isn't undone
> >until the rwsem_down_read_failed() function grabs the wait_lock. If the
> >wait_lock is contended, it may takes a while to get the lock. During
> >that period, writer lock stealing will be disabled because of the
> >active read lock.
> >
> >This patch will release the active read lock ASAP so that writer lock
> >stealing can happen sooner. The only downside is when the reader is
> >the first one in the wait queue as it has to issue another atomic
> >operation to update the count.
> >
> >On a 4-socket Haswell machine running on a 4.7-rc1 tip-based kernel,
> >the fio test with multithreaded randrw and randwrite tests on the
> >same file on a XFS partition on top of a NVDIMM with DAX were run,
> >the aggregated bandwidths before and after the patch were as follows:
> >
> > Test      BW before patch     BW after patch  % change
> > ----      ---------------     --------------  --------
> > randrw        1210 MB/s          1352 MB/s      +12%
> > randwrite     1622 MB/s          1710 MB/s      +5.4%
> 
> Yeah, this is really a bad workload to make decisions on locking
> heuristics imo - if I'm thinking of the same workload. Mainly because
> concurrent buffered io to the same file isn't very realistic and you
> end up pathologically pounding on i_rwsem (which used to be until
> recently i_mutex until Al's parallel lookup/readdir). Obviously write
> lock stealing wins in this case.

Except that it's DAX, and in 4.7-rc1 that used shared locking at the
XFS level and never took exclusive locks.

*However*, the DAX IO path locking in XFS  has changed in 4.9-rc1 to
match the buffered IO single writer POSIX semantics - the test is a
bad test based on the fact it exercised a path that is under heavy
development and so can't be used as a regression test across
multiple kernels.

If you want to stress concurrent access to a single file, please
use direct IO, not DAX or buffered IO.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

Re: [RFC PATCH-tip v4 02/10] locking/rwsem: Stop active read lock ASAP

[Davidlohr Bueso]

On Fri, 07 Oct 2016, Dave Chinner wrote:

>Except that it's DAX

Duh, of course; silly me.

Thanks,
Davidlohr

Re: [RFC PATCH-tip v4 02/10] locking/rwsem: Stop active read lock ASAP

[Waiman Long]

On 10/06/2016 05:47 PM, Dave Chinner wrote:
> On Thu, Oct 06, 2016 at 11:17:18AM -0700, Davidlohr Bueso wrote:
>> On Thu, 18 Aug 2016, Waiman Long wrote:
>>
>>> Currently, when down_read() fails, the active read locking isn't undone
>>> until the rwsem_down_read_failed() function grabs the wait_lock. If the
>>> wait_lock is contended, it may takes a while to get the lock. During
>>> that period, writer lock stealing will be disabled because of the
>>> active read lock.
>>>
>>> This patch will release the active read lock ASAP so that writer lock
>>> stealing can happen sooner. The only downside is when the reader is
>>> the first one in the wait queue as it has to issue another atomic
>>> operation to update the count.
>>>
>>> On a 4-socket Haswell machine running on a 4.7-rc1 tip-based kernel,
>>> the fio test with multithreaded randrw and randwrite tests on the
>>> same file on a XFS partition on top of a NVDIMM with DAX were run,
>>> the aggregated bandwidths before and after the patch were as follows:
>>>
>>> Test      BW before patch     BW after patch  % change
>>> ----      ---------------     --------------  --------
>>> randrw        1210 MB/s          1352 MB/s      +12%
>>> randwrite     1622 MB/s          1710 MB/s      +5.4%
>> Yeah, this is really a bad workload to make decisions on locking
>> heuristics imo - if I'm thinking of the same workload. Mainly because
>> concurrent buffered io to the same file isn't very realistic and you
>> end up pathologically pounding on i_rwsem (which used to be until
>> recently i_mutex until Al's parallel lookup/readdir). Obviously write
>> lock stealing wins in this case.
> Except that it's DAX, and in 4.7-rc1 that used shared locking at the
> XFS level and never took exclusive locks.
>
> *However*, the DAX IO path locking in XFS  has changed in 4.9-rc1 to
> match the buffered IO single writer POSIX semantics - the test is a
> bad test based on the fact it exercised a path that is under heavy
> development and so can't be used as a regression test across
> multiple kernels.
>
> If you want to stress concurrent access to a single file, please
> use direct IO, not DAX or buffered IO.

Thanks for the update. I will change the test when I update this patch.

Cheers,
Longman

Re: [RFC PATCH-tip v4 02/10] locking/rwsem: Stop active read lock ASAP

[Christoph Hellwig]

On Fri, Oct 07, 2016 at 08:47:51AM +1100, Dave Chinner wrote:
> Except that it's DAX, and in 4.7-rc1 that used shared locking at the
> XFS level and never took exclusive locks.
> 
> *However*, the DAX IO path locking in XFS  has changed in 4.9-rc1 to
> match the buffered IO single writer POSIX semantics - the test is a
> bad test based on the fact it exercised a path that is under heavy
> development and so can't be used as a regression test across
> multiple kernels.

That being said - I wonder if we should allow the shared lock on DAX
files IFF the user is specifying O_DIRECT in the open mode..

Re: [RFC PATCH-tip v4 02/10] locking/rwsem: Stop active read lock ASAP

[Dave Chinner]

On Sun, Oct 09, 2016 at 08:17:48AM -0700, Christoph Hellwig wrote:
> On Fri, Oct 07, 2016 at 08:47:51AM +1100, Dave Chinner wrote:
> > Except that it's DAX, and in 4.7-rc1 that used shared locking at the
> > XFS level and never took exclusive locks.
> > 
> > *However*, the DAX IO path locking in XFS  has changed in 4.9-rc1 to
> > match the buffered IO single writer POSIX semantics - the test is a
> > bad test based on the fact it exercised a path that is under heavy
> > development and so can't be used as a regression test across
> > multiple kernels.
> 
> That being said - I wonder if we should allow the shared lock on DAX
> files IFF the user is specifying O_DIRECT in the open mode..

It should do - if it doesn't then we screwed up the IO path
selection logic in XFS and we'll need to fix it.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

Re: [RFC PATCH-tip v4 02/10] locking/rwsem: Stop active read lock ASAP

[Christoph Hellwig]

On Mon, Oct 10, 2016 at 05:07:45PM +1100, Dave Chinner wrote:
> > > *However*, the DAX IO path locking in XFS  has changed in 4.9-rc1 to
> > > match the buffered IO single writer POSIX semantics - the test is a
> > > bad test based on the fact it exercised a path that is under heavy
> > > development and so can't be used as a regression test across
> > > multiple kernels.
> > 
> > That being said - I wonder if we should allow the shared lock on DAX
> > files IFF the user is specifying O_DIRECT in the open mode..
> 
> It should do - if it doesn't then we screwed up the IO path
> selection logic in XFS and we'll need to fix it.

Depends on your defintion of "we".  The DAX code has always abused the
direct I/O path, and that abuse is ingrained in the VFS path in a way that
we can't easily undo it in XFS, e.g. take a look at io_is_direct and
iocb_flags in include/linux/fs.h, which ensure that DAX I/O will always
appear as IOCB_DIRECT to the fs.  It will take some time to untagle
this, but it's on my todo list once the last file system (ext4)
untangles the DAX and direct I/O path.

Re: [RFC PATCH-tip v4 02/10] locking/rwsem: Stop active read lock ASAP

[Dave Chinner]

On Mon, Oct 10, 2016 at 02:34:34AM -0700, Christoph Hellwig wrote:
> On Mon, Oct 10, 2016 at 05:07:45PM +1100, Dave Chinner wrote:
> > > > *However*, the DAX IO path locking in XFS  has changed in 4.9-rc1 to
> > > > match the buffered IO single writer POSIX semantics - the test is a
> > > > bad test based on the fact it exercised a path that is under heavy
> > > > development and so can't be used as a regression test across
> > > > multiple kernels.
> > > 
> > > That being said - I wonder if we should allow the shared lock on DAX
> > > files IFF the user is specifying O_DIRECT in the open mode..
> > 
> > It should do - if it doesn't then we screwed up the IO path
> > selection logic in XFS and we'll need to fix it.
> 
> Depends on your defintion of "we".  The DAX code has always abused the
> direct I/O path, and that abuse is ingrained in the VFS path in a way that
> we can't easily undo it in XFS, e.g. take a look at io_is_direct and
> iocb_flags in include/linux/fs.h, which ensure that DAX I/O will always
> appear as IOCB_DIRECT to the fs. 

Um, I seem to have completely missed that change - when did that
happen and why?

Oh, it was part of the misguided "enable DAX on block devices"
changes - it was supposed to fix a problem with block device access
using buffered IO instead of DAX (commit 65f87ee71852 "fs, block:
force direct-I/O for dax-enabled block devices")).  The original
block device DAX code was reverted soon after this because it was
badly flawed, but this change was not removed at the same time
(probably because it was forgotton about).

Hence I'd suggest that DAX check in io_is_direct() should be removed
ASAP; the filesystems don't need it as they check the inode DAX
state directly, and the code it "fixed" is no longer in the tree.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

Re: [RFC PATCH-tip v4 02/10] locking/rwsem: Stop active read lock ASAP

[Christoph Hellwig]

On Wed, Oct 12, 2016 at 08:06:40AM +1100, Dave Chinner wrote:
> Um, I seem to have completely missed that change - when did that
> happen and why?
> 
> Oh, it was part of the misguided "enable DAX on block devices"
> changes -

o, that commit just switched it to use ->f_mapping:

-       return (filp->f_flags & O_DIRECT) || IS_DAX(file_inode(filp));
+       return (filp->f_flags & O_DIRECT) || IS_DAX(filp->f_mapping->host);

The original version of it goes all the way back to introducing the
current-day DAX code in d475c6346 ("dax,ext2: replace XIP read and write
with DAX I/O");

> Hence I'd suggest that DAX check in io_is_direct() should be removed
> ASAP; the filesystems don't need it as they check the inode DAX
> state directly, and the code it "fixed" is no longer in the tree.

As long as ext4 still uses the overloaded direct_IO we need the
checks for DAX in the filemap.c generic read/write code.  It seems
like that's only two spots anyway, but I'd feel much safer once ext4
is switched over to the iomap version of the dax code.

[RFC PATCH-tip v4 03/10] locking/rwsem: Make rwsem_spin_on_owner() return a tri-state value

[Waiman Long]

This patch modifies rwsem_spin_on_owner() to return a tri-state value
to better reflect the state of lock holder which enables us to make a
better decision of what to do next.

Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
---
 kernel/locking/rwsem-xadd.c |   14 +++++++++-----
 1 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 9309e72..31cb286 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -352,9 +352,13 @@ done:
 }
 
 /*
- * Return true only if we can still spin on the owner field of the rwsem.
+ * Return the folowing three values depending on the lock owner state.
+ *   1	when owner has changed and no reader is detected yet.
+ *   0	when owner has change and/or owner is a reader.
+ *  -1	when optimistic spinning has to stop because either the owner stops
+ *	running or its timeslice has been used up.
  */
-static noinline bool rwsem_spin_on_owner(struct rw_semaphore *sem)
+static noinline int rwsem_spin_on_owner(struct rw_semaphore *sem)
 {
 	struct task_struct *owner = READ_ONCE(sem->owner);
 
@@ -374,7 +378,7 @@ static noinline bool rwsem_spin_on_owner(struct rw_semaphore *sem)
 		/* abort spinning when need_resched or owner is not running */
 		if (!owner->on_cpu || need_resched()) {
 			rcu_read_unlock();
-			return false;
+			return -1;
 		}
 
 		cpu_relax_lowlatency();
@@ -385,7 +389,7 @@ out:
 	 * If there is a new owner or the owner is not set, we continue
 	 * spinning.
 	 */
-	return !rwsem_owner_is_reader(READ_ONCE(sem->owner));
+	return rwsem_owner_is_reader(READ_ONCE(sem->owner)) ? 0 : 1;
 }
 
 static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
@@ -408,7 +412,7 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
 	 *  2) readers own the lock as we can't determine if they are
 	 *     actively running or not.
 	 */
-	while (rwsem_spin_on_owner(sem)) {
+	while (rwsem_spin_on_owner(sem) > 0) {
 		/*
 		 * Try to acquire the lock
 		 */
-- 
1.7.1

[RFC PATCH-tip v4 04/10] locking/rwsem: Enable count-based spinning on reader

[Waiman Long]

When the rwsem is owned by reader, writers stop optimistic spinning
simply because there is no easy way to figure out if all the readers
are actively running or not. However, there are scenarios where
the readers are unlikely to sleep and optimistic spinning can help
performance.

This patch provides an autotuning mechanism to find out if a rwsem
can benefit from count-based reader optimistic spinning. A count
(rspin_enabled) in the rwsem data structure is used to track if
optimistic spinning should be enabled. Reader spinning is enabled
by default. Each successful spin (with lock acquisition) will
increment the count by 1 and each unsuccessful spin will decrement
it by 4.  When the count reaches 0, reader spinning is disabled.
Modification of that count is protected by the osq lock. Therefore,
reader spinning will be maintained as long as at least 80% of the
spins are successful.

Both the spinning threshold and the default value for rspin_enabled
can be overridden by architecture specific rwsem.h header file.

Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
---
 include/linux/rwsem.h       |   19 +++++++++++-
 kernel/locking/rwsem-xadd.c |   66 ++++++++++++++++++++++++++++++++++++++----
 2 files changed, 77 insertions(+), 8 deletions(-)

diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index dd1d142..8978f87 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -32,6 +32,8 @@ struct rw_semaphore {
 	raw_spinlock_t wait_lock;
 #ifdef CONFIG_RWSEM_SPIN_ON_OWNER
 	struct optimistic_spin_queue osq; /* spinner MCS lock */
+	int rspin_enabled;	/* protected by osq lock */
+
 	/*
 	 * Write owner. Used as a speculative check to see
 	 * if the owner is running on the cpu.
@@ -69,8 +71,23 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem)
 # define __RWSEM_DEP_MAP_INIT(lockname)
 #endif
 
+/*
+ * Each successful reader spin will increment the rspin_enabled by 1.
+ * Each unsuccessful spin, on the other hand, will decrement it by 2.
+ * Reader spinning will be permanently disabled when it reaches 0.
+ */
+#ifndef RWSEM_RSPIN_ENABLED_DEFAULT
+# define RWSEM_RSPIN_ENABLED_DEFAULT	40
+#endif
+#define RWSEM_RSPIN_ENABLED_MAX		1024
+
+#ifndef RWSEM_RSPIN_THRESHOLD
+# define RWSEM_RSPIN_THRESHOLD	(1 << 12)
+#endif
+
 #ifdef CONFIG_RWSEM_SPIN_ON_OWNER
-#define __RWSEM_OPT_INIT(lockname) , .osq = OSQ_LOCK_UNLOCKED, .owner = NULL
+#define __RWSEM_OPT_INIT(lockname) , .osq = OSQ_LOCK_UNLOCKED, .owner = NULL, \
+		.rspin_enabled = RWSEM_RSPIN_ENABLED_DEFAULT
 #else
 #define __RWSEM_OPT_INIT(lockname)
 #endif
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 31cb286..4654624 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -85,6 +85,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name,
 	INIT_LIST_HEAD(&sem->wait_list);
 #ifdef CONFIG_RWSEM_SPIN_ON_OWNER
 	sem->owner = NULL;
+	sem->rspin_enabled = RWSEM_RSPIN_ENABLED_DEFAULT;
 	osq_lock_init(&sem->osq);
 #endif
 }
@@ -339,9 +340,10 @@ static inline bool rwsem_can_spin_on_owner(struct rw_semaphore *sem)
 	owner = READ_ONCE(sem->owner);
 	if (!rwsem_owner_is_writer(owner)) {
 		/*
-		 * Don't spin if the rwsem is readers owned.
+		 * Don't spin if the rwsem is readers owned and the
+		 * reader spinning threshold isn't set.
 		 */
-		ret = !rwsem_owner_is_reader(owner);
+		ret = !rwsem_owner_is_reader(owner) || sem->rspin_enabled;
 		goto done;
 	}
 
@@ -395,6 +397,8 @@ out:
 static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
 {
 	bool taken = false;
+	int owner_state;	/* Lock owner state */
+	int rspin_cnt;		/* Count for reader spinning */
 
 	preempt_disable();
 
@@ -405,14 +409,16 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
 	if (!osq_lock(&sem->osq))
 		goto done;
 
+	rspin_cnt = sem->rspin_enabled ? RWSEM_RSPIN_THRESHOLD : 0;
+
 	/*
 	 * Optimistically spin on the owner field and attempt to acquire the
 	 * lock whenever the owner changes. Spinning will be stopped when:
-	 *  1) the owning writer isn't running; or
-	 *  2) readers own the lock as we can't determine if they are
-	 *     actively running or not.
+	 *  1) the owning writer isn't running,
+	 *  2) readers own the lock and reader spinning count has reached 0; or
+	 *  3) its timeslice has been used up.
 	 */
-	while (rwsem_spin_on_owner(sem) > 0) {
+	while ((owner_state = rwsem_spin_on_owner(sem)) >= 0) {
 		/*
 		 * Try to acquire the lock
 		 */
@@ -422,12 +428,24 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
 		}
 
 		/*
+		 * We only decremnt the rspin_cnt when the lock is owned
+		 * by readers (owner_state == 0). In which case,
+		 * rwsem_spin_on_owner() will essentially be a no-op
+		 * and we will be spinning in this main loop.
+		 */
+		if (owner_state == 0) {
+			if (!rspin_cnt)
+				break;
+			rspin_cnt--;
+		}
+
+		/*
 		 * When there's no owner, we might have preempted between the
 		 * owner acquiring the lock and setting the owner field. If
 		 * we're an RT task that will live-lock because we won't let
 		 * the owner complete.
 		 */
-		if (!sem->owner && (need_resched() || rt_task(current)))
+		if (!sem->owner && rt_task(current))
 			break;
 
 		/*
@@ -438,6 +456,28 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
 		 */
 		cpu_relax_lowlatency();
 	}
+	/*
+	 * Check the success or failure of writer spinning on reader so as
+	 * to adjust the rspin_enabled count accordingly.
+	 */
+	if (rwsem_owner_is_reader(sem->owner)) {
+		/*
+		 * Update rspin_enabled for reader spinning.
+		 *
+		 * Right now, we need more than 2/3 successful spins to
+		 * maintain reader spinning. We will get rid of it if we don't
+		 * have enough successful spins. The decrement amount is kind
+		 * of arbitrary and can be adjusted if necessary.
+		 */
+		if (taken && (sem->rspin_enabled < RWSEM_RSPIN_ENABLED_MAX)) {
+			sem->rspin_enabled++;
+		} else if (!taken) {
+			if  (sem->rspin_enabled > 2)
+				sem->rspin_enabled -= 2;
+			else
+				sem->rspin_enabled = 0;
+		}
+	}
 	osq_unlock(&sem->osq);
 done:
 	preempt_enable();
@@ -452,6 +492,13 @@ static inline bool rwsem_has_spinner(struct rw_semaphore *sem)
 	return osq_is_locked(&sem->osq);
 }
 
+/*
+ * Return true if reader optimistic spinning is enabled
+ */
+static inline bool reader_spinning_enabled(struct rw_semaphore *sem)
+{
+	return sem->rspin_enabled;
+}
 #else
 static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
 {
@@ -462,6 +509,11 @@ static inline bool rwsem_has_spinner(struct rw_semaphore *sem)
 {
 	return false;
 }
+
+static inline bool reader_spinning_enabled(struct rw_semaphore *sem)
+{
+	return false;
+}
 #endif
 
 /*
-- 
1.7.1

[RFC PATCH-tip v4 05/10] locking/rwsem: move down rwsem_down_read_failed function

[Waiman Long]

Move the rwsem_down_read_failed() function down to below the
optimistic spinning section before enabling optimistic spinning for
the readers. It is because the rwsem_down_read_failed() function will
call rwsem_optimistic_spin() in later patch.

There is no change in code.

Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
---
 kernel/locking/rwsem-xadd.c |  116 +++++++++++++++++++++---------------------
 1 files changed, 58 insertions(+), 58 deletions(-)

diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 4654624..6b5bd6e 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -218,64 +218,6 @@ static void __rwsem_mark_wake(struct rw_semaphore *sem,
 }
 
 /*
- * Wait for the read lock to be granted
- */
-__visible
-struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem)
-{
-	long count, adjustment = 0;
-	struct rwsem_waiter waiter;
-	struct task_struct *tsk = current;
-	WAKE_Q(wake_q);
-
-	/*
-	 * Undo read bias from down_read operation to stop active locking.
-	 * Doing that after taking the wait_lock may block writer lock
-	 * stealing for too long impacting system performance.
-	 */
-	atomic_long_add(-RWSEM_ACTIVE_READ_BIAS, &sem->count);
-
-	waiter.task = tsk;
-	waiter.type = RWSEM_WAITING_FOR_READ;
-
-	raw_spin_lock_irq(&sem->wait_lock);
-	if (list_empty(&sem->wait_list))
-		adjustment = RWSEM_WAITING_BIAS;
-	list_add_tail(&waiter.list, &sem->wait_list);
-
-	/* we're now waiting on the lock */
-	if (adjustment)
-		count = atomic_long_add_return(adjustment, &sem->count);
-	else
-		count = atomic_long_read(&sem->count);
-
-	/*
-	 * If there are no active locks, wake the front queued process(es).
-	 *
-	 * If there are no writers and we are first in the queue,
-	 * wake our own waiter to join the existing active readers !
-	 */
-	if (count == RWSEM_WAITING_BIAS ||
-	    (count > RWSEM_WAITING_BIAS && adjustment))
-		__rwsem_mark_wake(sem, RWSEM_WAKE_ANY, &wake_q);
-
-	raw_spin_unlock_irq(&sem->wait_lock);
-	wake_up_q(&wake_q);
-
-	/* wait to be given the lock */
-	while (true) {
-		set_task_state(tsk, TASK_UNINTERRUPTIBLE);
-		if (!waiter.task)
-			break;
-		schedule();
-	}
-
-	__set_task_state(tsk, TASK_RUNNING);
-	return sem;
-}
-EXPORT_SYMBOL(rwsem_down_read_failed);
-
-/*
  * This function must be called with the sem->wait_lock held to prevent
  * race conditions between checking the rwsem wait list and setting the
  * sem->count accordingly.
@@ -517,6 +459,64 @@ static inline bool reader_spinning_enabled(struct rw_semaphore *sem)
 #endif
 
 /*
+ * Wait for the read lock to be granted
+ */
+__visible
+struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem)
+{
+	long count, adjustment = 0;
+	struct rwsem_waiter waiter;
+	struct task_struct *tsk = current;
+	WAKE_Q(wake_q);
+
+	/*
+	 * Undo read bias from down_read operation to stop active locking.
+	 * Doing that after taking the wait_lock may block writer lock
+	 * stealing for too long impacting system performance.
+	 */
+	atomic_long_add(-RWSEM_ACTIVE_READ_BIAS, &sem->count);
+
+	waiter.task = tsk;
+	waiter.type = RWSEM_WAITING_FOR_READ;
+
+	raw_spin_lock_irq(&sem->wait_lock);
+	if (list_empty(&sem->wait_list))
+		adjustment = RWSEM_WAITING_BIAS;
+	list_add_tail(&waiter.list, &sem->wait_list);
+
+	/* we're now waiting on the lock */
+	if (adjustment)
+		count = atomic_long_add_return(adjustment, &sem->count);
+	else
+		count = atomic_long_read(&sem->count);
+
+	/*
+	 * If there are no active locks, wake the front queued process(es).
+	 *
+	 * If there are no writers and we are first in the queue,
+	 * wake our own waiter to join the existing active readers !
+	 */
+	if (count == RWSEM_WAITING_BIAS ||
+	    (count > RWSEM_WAITING_BIAS && adjustment))
+		__rwsem_mark_wake(sem, RWSEM_WAKE_ANY, &wake_q);
+
+	raw_spin_unlock_irq(&sem->wait_lock);
+	wake_up_q(&wake_q);
+
+	/* wait to be given the lock */
+	while (true) {
+		set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+		if (!waiter.task)
+			break;
+		schedule();
+	}
+
+	__set_task_state(tsk, TASK_RUNNING);
+	return sem;
+}
+EXPORT_SYMBOL(rwsem_down_read_failed);
+
+/*
  * Wait until we successfully acquire the write lock
  */
 static inline struct rw_semaphore *
-- 
1.7.1

[RFC PATCH-tip v4 06/10] locking/rwsem: Move common rwsem macros to asm-generic/rwsem_types.h

[Waiman Long]

Almost all the macro definitions in the various architecture specific
rwsem.h header files are essentially the same. This patch moves all
of them into a common header asm-generic/rwsem_types.h to eliminate
the duplication.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
---
 arch/alpha/include/asm/rwsem.h    |    8 +-------
 arch/ia64/include/asm/rwsem.h     |    7 ++-----
 arch/s390/include/asm/rwsem.h     |    7 +------
 arch/x86/include/asm/rwsem.h      |   19 +------------------
 include/asm-generic/rwsem.h       |   16 +---------------
 include/asm-generic/rwsem_types.h |   26 ++++++++++++++++++++++++++
 6 files changed, 32 insertions(+), 51 deletions(-)
 create mode 100644 include/asm-generic/rwsem_types.h

diff --git a/arch/alpha/include/asm/rwsem.h b/arch/alpha/include/asm/rwsem.h
index 77873d0..f99e39a 100644
--- a/arch/alpha/include/asm/rwsem.h
+++ b/arch/alpha/include/asm/rwsem.h
@@ -13,13 +13,7 @@
 #ifdef __KERNEL__
 
 #include <linux/compiler.h>
-
-#define RWSEM_UNLOCKED_VALUE		0x0000000000000000L
-#define RWSEM_ACTIVE_BIAS		0x0000000000000001L
-#define RWSEM_ACTIVE_MASK		0x00000000ffffffffL
-#define RWSEM_WAITING_BIAS		(-0x0000000100000000L)
-#define RWSEM_ACTIVE_READ_BIAS		RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS		(RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
+#include <asm-generic/rwsem_types.h>
 
 static inline void __down_read(struct rw_semaphore *sem)
 {
diff --git a/arch/ia64/include/asm/rwsem.h b/arch/ia64/include/asm/rwsem.h
index 8fa98dd..21a9066 100644
--- a/arch/ia64/include/asm/rwsem.h
+++ b/arch/ia64/include/asm/rwsem.h
@@ -26,13 +26,10 @@
 #endif
 
 #include <asm/intrinsics.h>
+#include <asm-generic/rwsem_types.h>
 
+#undef  RWSEM_UNLOCKED_VALUE
 #define RWSEM_UNLOCKED_VALUE		__IA64_UL_CONST(0x0000000000000000)
-#define RWSEM_ACTIVE_BIAS		(1L)
-#define RWSEM_ACTIVE_MASK		(0xffffffffL)
-#define RWSEM_WAITING_BIAS		(-0x100000000L)
-#define RWSEM_ACTIVE_READ_BIAS		RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS		(RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
 
 /*
  * lock for reading
diff --git a/arch/s390/include/asm/rwsem.h b/arch/s390/include/asm/rwsem.h
index 597e7e9..13dedc8 100644
--- a/arch/s390/include/asm/rwsem.h
+++ b/arch/s390/include/asm/rwsem.h
@@ -39,12 +39,7 @@
 #error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead"
 #endif
 
-#define RWSEM_UNLOCKED_VALUE	0x0000000000000000L
-#define RWSEM_ACTIVE_BIAS	0x0000000000000001L
-#define RWSEM_ACTIVE_MASK	0x00000000ffffffffL
-#define RWSEM_WAITING_BIAS	(-0x0000000100000000L)
-#define RWSEM_ACTIVE_READ_BIAS	RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS	(RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
+#include <asm-generic/rwsem_types.h>
 
 /*
  * lock for reading
diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h
index 8dbc762..da84726 100644
--- a/arch/x86/include/asm/rwsem.h
+++ b/arch/x86/include/asm/rwsem.h
@@ -38,24 +38,7 @@
 
 #ifdef __KERNEL__
 #include <asm/asm.h>
-
-/*
- * The bias values and the counter type limits the number of
- * potential readers/writers to 32767 for 32 bits and 2147483647
- * for 64 bits.
- */
-
-#ifdef CONFIG_X86_64
-# define RWSEM_ACTIVE_MASK		0xffffffffL
-#else
-# define RWSEM_ACTIVE_MASK		0x0000ffffL
-#endif
-
-#define RWSEM_UNLOCKED_VALUE		0x00000000L
-#define RWSEM_ACTIVE_BIAS		0x00000001L
-#define RWSEM_WAITING_BIAS		(-RWSEM_ACTIVE_MASK-1)
-#define RWSEM_ACTIVE_READ_BIAS		RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS		(RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
+#include <asm-generic/rwsem_types.h>
 
 /*
  * lock for reading
diff --git a/include/asm-generic/rwsem.h b/include/asm-generic/rwsem.h
index 5be122e..3cb8d98 100644
--- a/include/asm-generic/rwsem.h
+++ b/include/asm-generic/rwsem.h
@@ -12,21 +12,7 @@
  * Adapted largely from include/asm-i386/rwsem.h
  * by Paul Mackerras <paulus@samba.org>.
  */
-
-/*
- * the semaphore definition
- */
-#ifdef CONFIG_64BIT
-# define RWSEM_ACTIVE_MASK		0xffffffffL
-#else
-# define RWSEM_ACTIVE_MASK		0x0000ffffL
-#endif
-
-#define RWSEM_UNLOCKED_VALUE		0x00000000L
-#define RWSEM_ACTIVE_BIAS		0x00000001L
-#define RWSEM_WAITING_BIAS		(-RWSEM_ACTIVE_MASK-1)
-#define RWSEM_ACTIVE_READ_BIAS		RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS		(RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
+#include <asm-generic/rwsem_types.h>
 
 /*
  * lock for reading
diff --git a/include/asm-generic/rwsem_types.h b/include/asm-generic/rwsem_types.h
new file mode 100644
index 0000000..093ef6a
--- /dev/null
+++ b/include/asm-generic/rwsem_types.h
@@ -0,0 +1,26 @@
+#ifndef _ASM_GENERIC_RWSEM_TYPES_H
+#define _ASM_GENERIC_RWSEM_TYPES_H
+
+#ifdef __KERNEL__
+
+/*
+ * the semaphore definition
+ *
+ * The bias values and the counter type limits the number of
+ * potential readers/writers to 32767 for 32 bits and 2147483647
+ * for 64 bits.
+ */
+#ifdef CONFIG_64BIT
+# define RWSEM_ACTIVE_MASK		0xffffffffL
+#else
+# define RWSEM_ACTIVE_MASK		0x0000ffffL
+#endif
+
+#define RWSEM_UNLOCKED_VALUE		0x00000000L
+#define RWSEM_ACTIVE_BIAS		0x00000001L
+#define RWSEM_WAITING_BIAS		(-RWSEM_ACTIVE_MASK-1)
+#define RWSEM_ACTIVE_READ_BIAS		RWSEM_ACTIVE_BIAS
+#define RWSEM_ACTIVE_WRITE_BIAS		(RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
+
+#endif	/* __KERNEL__ */
+#endif	/* _ASM_GENERIC_RWSEM_TYPES_H */
-- 
1.7.1

[RFC PATCH-tip v4 07/10] locking/rwsem: Change RWSEM_WAITING_BIAS for better disambiguation

[Waiman Long]

When the count value is in between 0 and RWSEM_WAITING_BIAS, there
are 2 possibilities. Either a writer is present and there is no
waiter or there are waiters and readers. There is no easy way to
know which is true unless the wait_lock is taken.

This patch changes the RWSEM_WAITING_BIAS from 0xffff (32-bit) or
0xffffffff (64-bit) to 0xc0000000 (32-bit) or 0xc000000000000000
(64-bit). By doing so, we will be able to determine if writers
are present by looking at the count value alone without taking the
wait_lock.

This patch has the effect of halving the maximum number of writers
that can attempt to take the write lock simultaneously. However,
even the reduced maximum of about 16k (32-bit) or 1G (64-bit) should
be more than enough for the foreseeable future.

With that change, the following identity is now no longer true:

  RWSEM_ACTIVE_WRITE_BIAS = RWSEM_WAITING_BIAS + RWSEM_ACTIVE_READ_BIAS

Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
---
 arch/alpha/include/asm/rwsem.h    |    3 ++-
 arch/ia64/include/asm/rwsem.h     |    2 +-
 arch/s390/include/asm/rwsem.h     |    2 +-
 arch/x86/include/asm/rwsem.h      |    3 ++-
 include/asm-generic/rwsem.h       |    4 ++--
 include/asm-generic/rwsem_types.h |   10 ++++++----
 kernel/locking/rwsem-xadd.c       |   32 ++++++++++++++++++++++++--------
 7 files changed, 38 insertions(+), 18 deletions(-)

diff --git a/arch/alpha/include/asm/rwsem.h b/arch/alpha/include/asm/rwsem.h
index f99e39a..dc236a5 100644
--- a/arch/alpha/include/asm/rwsem.h
+++ b/arch/alpha/include/asm/rwsem.h
@@ -179,7 +179,8 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
 	"2:	br	1b\n"
 	".previous"
 	:"=&r" (oldcount), "=m" (sem->count), "=&r" (temp)
-	:"Ir" (-RWSEM_WAITING_BIAS), "m" (sem->count) : "memory");
+	:"Ir" (-RWSEM_ACTIVE_WRITE_BIAS + RWSEM_ACTIVE_READ_BIAS),
+	 "m" (sem->count) : "memory");
 #endif
 	if (unlikely(oldcount < 0))
 		rwsem_downgrade_wake(sem);
diff --git a/arch/ia64/include/asm/rwsem.h b/arch/ia64/include/asm/rwsem.h
index 21a9066..ecea341 100644
--- a/arch/ia64/include/asm/rwsem.h
+++ b/arch/ia64/include/asm/rwsem.h
@@ -141,7 +141,7 @@ __downgrade_write (struct rw_semaphore *sem)
 
 	do {
 		old = atomic_long_read(&sem->count);
-		new = old - RWSEM_WAITING_BIAS;
+		new = old - RWSEM_ACTIVE_WRITE_BIAS + RWSEM_ACTIVE_READ_BIAS;
 	} while (atomic_long_cmpxchg_release(&sem->count, old, new) != old);
 
 	if (old < 0)
diff --git a/arch/s390/include/asm/rwsem.h b/arch/s390/include/asm/rwsem.h
index 13dedc8..e675a64 100644
--- a/arch/s390/include/asm/rwsem.h
+++ b/arch/s390/include/asm/rwsem.h
@@ -188,7 +188,7 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
 {
 	signed long old, new, tmp;
 
-	tmp = -RWSEM_WAITING_BIAS;
+	tmp = -RWSEM_ACTIVE_WRITE_BIAS + RWSEM_ACTIVE_READ_BIAS;
 	asm volatile(
 		"	lg	%0,%2\n"
 		"0:	lgr	%1,%0\n"
diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h
index da84726..1edea1a 100644
--- a/arch/x86/include/asm/rwsem.h
+++ b/arch/x86/include/asm/rwsem.h
@@ -193,7 +193,8 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
 		     "1:\n\t"
 		     "# ending __downgrade_write\n"
 		     : "+m" (sem->count)
-		     : "a" (sem), "er" (-RWSEM_WAITING_BIAS)
+		     : "a" (sem), "er" (-RWSEM_ACTIVE_WRITE_BIAS +
+					 RWSEM_ACTIVE_READ_BIAS)
 		     : "memory", "cc");
 }
 
diff --git a/include/asm-generic/rwsem.h b/include/asm-generic/rwsem.h
index 3cb8d98..962e75b 100644
--- a/include/asm-generic/rwsem.h
+++ b/include/asm-generic/rwsem.h
@@ -106,8 +106,8 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
 	 * read-locked region is ok to be re-ordered into the
 	 * write side. As such, rely on RELEASE semantics.
 	 */
-	tmp = atomic_long_add_return_release(-RWSEM_WAITING_BIAS,
-				     (atomic_long_t *)&sem->count);
+	tmp = atomic_long_add_return_release(-RWSEM_ACTIVE_WRITE_BIAS +
+			RWSEM_ACTIVE_READ_BIAS, (atomic_long_t *)&sem->count);
 	if (tmp < 0)
 		rwsem_downgrade_wake(sem);
 }
diff --git a/include/asm-generic/rwsem_types.h b/include/asm-generic/rwsem_types.h
index 093ef6a..6d55d25 100644
--- a/include/asm-generic/rwsem_types.h
+++ b/include/asm-generic/rwsem_types.h
@@ -7,20 +7,22 @@
  * the semaphore definition
  *
  * The bias values and the counter type limits the number of
- * potential readers/writers to 32767 for 32 bits and 2147483647
- * for 64 bits.
+ * potential writers to 16383 for 32 bits and 1073741823 for 64 bits.
+ * The combined readers and writers can go up to 65534 for 32-bits and
+ * 4294967294 for 64-bits.
  */
 #ifdef CONFIG_64BIT
 # define RWSEM_ACTIVE_MASK		0xffffffffL
+# define RWSEM_WAITING_BIAS		(-(1L << 62))
 #else
 # define RWSEM_ACTIVE_MASK		0x0000ffffL
+# define RWSEM_WAITING_BIAS		(-(1L << 30))
 #endif
 
 #define RWSEM_UNLOCKED_VALUE		0x00000000L
 #define RWSEM_ACTIVE_BIAS		0x00000001L
-#define RWSEM_WAITING_BIAS		(-RWSEM_ACTIVE_MASK-1)
 #define RWSEM_ACTIVE_READ_BIAS		RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS		(RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
+#define RWSEM_ACTIVE_WRITE_BIAS		(-RWSEM_ACTIVE_MASK)
 
 #endif	/* __KERNEL__ */
 #endif	/* _ASM_GENERIC_RWSEM_TYPES_H */
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 6b5bd6e..8b118b3 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -29,28 +29,30 @@
  * 0x00000000	rwsem is unlocked, and no one is waiting for the lock or
  *		attempting to read lock or write lock.
  *
- * 0xffff000X	(1) X readers active or attempting lock, with waiters for lock
+ * 0xc000000X	(1) X readers active or attempting lock, with waiters for lock
  *		    X = #active readers + # readers attempting lock
  *		    (X*ACTIVE_BIAS + WAITING_BIAS)
- *		(2) 1 writer attempting lock, no waiters for lock
+ *
+ * 0xffff000X	(1) 1 writer attempting lock, no waiters for lock
  *		    X-1 = #active readers + #readers attempting lock
  *		    ((X-1)*ACTIVE_BIAS + ACTIVE_WRITE_BIAS)
- *		(3) 1 writer active, no waiters for lock
+ *		(2) 1 writer active, no waiters for lock
  *		    X-1 = #active readers + #readers attempting lock
  *		    ((X-1)*ACTIVE_BIAS + ACTIVE_WRITE_BIAS)
  *
- * 0xffff0001	(1) 1 reader active or attempting lock, waiters for lock
+ * 0xc0000001	(1) 1 reader active or attempting lock, waiters for lock
  *		    (WAITING_BIAS + ACTIVE_BIAS)
- *		(2) 1 writer active or attempting lock, no waiters for lock
+ *
+ * 0xffff0001	(1) 1 writer active or attempting lock, no waiters for lock
  *		    (ACTIVE_WRITE_BIAS)
  *
- * 0xffff0000	(1) There are writers or readers queued but none active
+ * 0xc0000000	(1) There are writers or readers queued but none active
  *		    or in the process of attempting lock.
  *		    (WAITING_BIAS)
  *		Note: writer can attempt to steal lock for this count by adding
  *		ACTIVE_WRITE_BIAS in cmpxchg and checking the old count
  *
- * 0xfffe0001	(1) 1 writer active, or attempting lock. Waiters on queue.
+ * 0xbfff0001	(1) 1 writer active, or attempting lock. Waiters on queue.
  *		    (ACTIVE_WRITE_BIAS + WAITING_BIAS)
  *
  * Note: Readers attempt to lock by adding ACTIVE_BIAS in down_read and checking
@@ -62,9 +64,23 @@
  *	 checking the count becomes ACTIVE_WRITE_BIAS for successful lock
  *	 acquisition (i.e. nobody else has lock or attempts lock).  If
  *	 unsuccessful, in rwsem_down_write_failed, we'll check to see if there
- *	 are only waiters but none active (5th case above), and attempt to
+ *	 are only waiters but none active (7th case above), and attempt to
  *	 steal the lock.
  *
+ *	 We can infer the reader/writer/waiter state of the lock by looking
+ *	 at the count value:
+ *	 (1) count > 0
+ *	     Only readers are present.
+ *	 (2) WAITING_BIAS - ACTIVE_WRITE_BIAS < count < 0
+ *	     Have writers, maybe readers, but no waiter
+ *	 (3) WAITING_BIAS < count <= WAITING_BIAS - ACTIVE_WRITE_BIAS
+ *	     Have readers and waiters, but no writer
+ *	 (4) count < WAITING_BIAS
+ *	     Have writers and waiters, maybe readers
+ *
+ *	 IOW, writers are present when
+ *	 (1) count < WAITING_BIAS, or
+ *	 (2) WAITING_BIAS - ACTIVE_WRITE_BIAS < count < 0
  */
 
 /*
-- 
1.7.1

Re: [RFC PATCH-tip v4 07/10] locking/rwsem: Change RWSEM_WAITING_BIAS for better disambiguation

[Wanpeng Li]

2016-08-19 5:11 GMT+08:00 Waiman Long <Waiman.Long@hpe.com>:
> When the count value is in between 0 and RWSEM_WAITING_BIAS, there
> are 2 possibilities.
> Either a writer is present and there is no waiter

count = 0xffff0001

>or there are waiters and readers. There is no easy way to

count = 0xffff000X

However, RWSEM_WAITING_BIAS is equal to 0xffff0000, so both these two
cases are beyond RWSEM_WAITING_BIAS, right?

Regards,
Wanpeng Li

Re: [RFC PATCH-tip v4 07/10] locking/rwsem: Change RWSEM_WAITING_BIAS for better disambiguation

[Waiman Long]

On 08/19/2016 01:57 AM, Wanpeng Li wrote:
> 2016-08-19 5:11 GMT+08:00 Waiman Long<Waiman.Long@hpe.com>:
>> When the count value is in between 0 and RWSEM_WAITING_BIAS, there
>> are 2 possibilities.
>> Either a writer is present and there is no waiter
> count = 0xffff0001
>
>> or there are waiters and readers. There is no easy way to
> count = 0xffff000X
>
> However, RWSEM_WAITING_BIAS is equal to 0xffff0000, so both these two
> cases are beyond RWSEM_WAITING_BIAS, right?
>
> Regards,
> Wanpeng Li

Perhaps I should make it clear that I am talking from a signed quantity 
point of view (it is an atomic_long_t). So

     RWSEM_WAITING_BIAS < RWSEM_ACTIVE_WRITE_BIAS < 0

Hope this clarify your question.

Cheers,
Longman

Re: [RFC PATCH-tip v4 07/10] locking/rwsem: Change RWSEM_WAITING_BIAS for better disambiguation

[Wanpeng Li]

2016-08-20 0:21 GMT+08:00 Waiman Long <waiman.long@hpe.com>:
> On 08/19/2016 01:57 AM, Wanpeng Li wrote:
>>
>> 2016-08-19 5:11 GMT+08:00 Waiman Long<Waiman.Long@hpe.com>:
>>>
>>> When the count value is in between 0 and RWSEM_WAITING_BIAS, there
>>> are 2 possibilities.
>>> Either a writer is present and there is no waiter
>>
>> count = 0xffff0001
>>
>>> or there are waiters and readers. There is no easy way to
>>
>> count = 0xffff000X
>>
>> However, RWSEM_WAITING_BIAS is equal to 0xffff0000, so both these two
>> cases are beyond RWSEM_WAITING_BIAS, right?
>>
>> Regards,
>> Wanpeng Li
>
>
> Perhaps I should make it clear that I am talking from a signed quantity
> point of view (it is an atomic_long_t). So
>
>     RWSEM_WAITING_BIAS < RWSEM_ACTIVE_WRITE_BIAS < 0
>
> Hope this clarify your question.

Yeah, thank you. :)

Regards,
Wanpeng Li

[RFC PATCH-tip v4 08/10] locking/rwsem: Enable spinning readers

[Waiman Long]

This patch enables readers to optimistically spin when the
rspin_threshold is non-zero. That threshold value should only
be set when the lock owners of the rwsem are unlikely to go to
sleep. Otherwise enabling reader spinning may make the performance
worse in some cases.

On a 4-socket Haswell machine running on a 4.7-rc1 tip-based kernel,
the fio test with multithreaded randrw and randwrite tests on the
same file on a XFS partition on top of a NVDIMM with DAX were run,
the aggregated bandwidths before and after the reader optimistic
spinning patchset were as follows:

  Test      BW before patch     BW after patch  % change
  ----      ---------------     --------------  --------
  randrw        1352 MB/s          2164 MB/s      +60%
  randwrite     1710 MB/s          2550 MB/s      +49%

Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
---
 kernel/locking/rwsem-xadd.c |   48 ++++++++++++++++++++++++++++++++++++------
 1 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 8b118b3..d850214 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -83,6 +83,12 @@
  *	 (2) WAITING_BIAS - ACTIVE_WRITE_BIAS < count < 0
  */
 
+static inline bool count_has_writer(long count)
+{
+	return (count < RWSEM_WAITING_BIAS) || ((count < 0) &&
+	       (count > RWSEM_WAITING_BIAS - RWSEM_ACTIVE_WRITE_BIAS));
+}
+
 /*
  * Initialize an rwsem:
  */
@@ -286,6 +292,25 @@ static inline bool rwsem_try_write_lock_unqueued(struct rw_semaphore *sem)
 	}
 }
 
+/*
+ * Try to acquire read lock before the reader is put on wait queue
+ */
+static inline bool rwsem_try_read_lock_unqueued(struct rw_semaphore *sem)
+{
+	long count = atomic_long_read(&sem->count);
+
+	if (count_has_writer(count))
+		return false;
+	count = atomic_long_add_return_acquire(RWSEM_ACTIVE_READ_BIAS,
+					       &sem->count);
+	if (!count_has_writer(count))
+		return true;
+
+	/* Back out the change */
+	atomic_long_add(-RWSEM_ACTIVE_READ_BIAS, &sem->count);
+	return false;
+}
+
 static inline bool rwsem_can_spin_on_owner(struct rw_semaphore *sem)
 {
 	struct task_struct *owner;
@@ -352,7 +377,8 @@ out:
 	return rwsem_owner_is_reader(READ_ONCE(sem->owner)) ? 0 : 1;
 }
 
-static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
+static bool rwsem_optimistic_spin(struct rw_semaphore *sem,
+				  enum rwsem_waiter_type type)
 {
 	bool taken = false;
 	int owner_state;	/* Lock owner state */
@@ -380,10 +406,11 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
 		/*
 		 * Try to acquire the lock
 		 */
-		if (rwsem_try_write_lock_unqueued(sem)) {
-			taken = true;
+		taken = (type == RWSEM_WAITING_FOR_WRITE)
+		      ? rwsem_try_write_lock_unqueued(sem)
+		      : rwsem_try_read_lock_unqueued(sem);
+		if (taken)
 			break;
-		}
 
 		/*
 		 * We only decremnt the rspin_cnt when the lock is owned
@@ -418,7 +445,8 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
 	 * Check the success or failure of writer spinning on reader so as
 	 * to adjust the rspin_enabled count accordingly.
 	 */
-	if (rwsem_owner_is_reader(sem->owner)) {
+	if ((type == RWSEM_WAITING_FOR_WRITE) &&
+	    rwsem_owner_is_reader(sem->owner)) {
 		/*
 		 * Update rspin_enabled for reader spinning.
 		 *
@@ -458,7 +486,8 @@ static inline bool reader_spinning_enabled(struct rw_semaphore *sem)
 	return sem->rspin_enabled;
 }
 #else
-static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
+static bool rwsem_optimistic_spin(struct rw_semaphore *sem,
+				  enum rwsem_waiter_type type)
 {
 	return false;
 }
@@ -492,6 +521,11 @@ struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem)
 	 */
 	atomic_long_add(-RWSEM_ACTIVE_READ_BIAS, &sem->count);
 
+	/* do optimistic spinning and steal lock if possible */
+	if (reader_spinning_enabled(sem) &&
+	    rwsem_optimistic_spin(sem, RWSEM_WAITING_FOR_READ))
+		return sem;
+
 	waiter.task = tsk;
 	waiter.type = RWSEM_WAITING_FOR_READ;
 
@@ -548,7 +582,7 @@ __rwsem_down_write_failed_common(struct rw_semaphore *sem, int state)
 	count = atomic_long_sub_return(RWSEM_ACTIVE_WRITE_BIAS, &sem->count);
 
 	/* do optimistic spinning and steal lock if possible */
-	if (rwsem_optimistic_spin(sem))
+	if (rwsem_optimistic_spin(sem, RWSEM_WAITING_FOR_WRITE))
 		return sem;
 
 	/*
-- 
1.7.1

[RFC PATCH-tip v4 09/10] locking/rwsem: Enable reactivation of reader spinning

[Waiman Long]

Reader optimistic spinning will be disabled once the rspin_enabled
count reaches 0. After that, it cannot be re-enabled. This may cause
an eligible rwsem locked out of reader spinning because of a series
of unfortunate events.

This patch looks at the regular writer-on-writer spinning history. If
there are sufficient more successful spin attempts than failed ones,
it will try to reactivate reader spinning.

Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
---
 include/linux/rwsem.h       |   12 ++++++++----
 kernel/locking/rwsem-xadd.c |   27 +++++++++++++++++++++++++--
 2 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 8978f87..98284b4 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -32,7 +32,11 @@ struct rw_semaphore {
 	raw_spinlock_t wait_lock;
 #ifdef CONFIG_RWSEM_SPIN_ON_OWNER
 	struct optimistic_spin_queue osq; /* spinner MCS lock */
-	int rspin_enabled;	/* protected by osq lock */
+	/*
+	 * Reader optimistic spinning fields protected by osq lock
+	 */
+	uint16_t rspin_enabled;
+	int16_t  wspin_cnt;
 
 	/*
 	 * Write owner. Used as a speculative check to see
@@ -74,10 +78,10 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem)
 /*
  * Each successful reader spin will increment the rspin_enabled by 1.
  * Each unsuccessful spin, on the other hand, will decrement it by 2.
- * Reader spinning will be permanently disabled when it reaches 0.
+ * Reader spinning will be disabled when it reaches 0.
  */
 #ifndef RWSEM_RSPIN_ENABLED_DEFAULT
-# define RWSEM_RSPIN_ENABLED_DEFAULT	40
+# define RWSEM_RSPIN_ENABLED_DEFAULT	30
 #endif
 #define RWSEM_RSPIN_ENABLED_MAX		1024
 
@@ -87,7 +91,7 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem)
 
 #ifdef CONFIG_RWSEM_SPIN_ON_OWNER
 #define __RWSEM_OPT_INIT(lockname) , .osq = OSQ_LOCK_UNLOCKED, .owner = NULL, \
-		.rspin_enabled = RWSEM_RSPIN_ENABLED_DEFAULT
+		.rspin_enabled = RWSEM_RSPIN_ENABLED_DEFAULT, .wspin_cnt = 0
 #else
 #define __RWSEM_OPT_INIT(lockname)
 #endif
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index d850214..9978159 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -108,6 +108,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name,
 #ifdef CONFIG_RWSEM_SPIN_ON_OWNER
 	sem->owner = NULL;
 	sem->rspin_enabled = RWSEM_RSPIN_ENABLED_DEFAULT;
+	sem->wspin_cnt = 0;
 	osq_lock_init(&sem->osq);
 #endif
 }
@@ -458,10 +459,32 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem,
 		if (taken && (sem->rspin_enabled < RWSEM_RSPIN_ENABLED_MAX)) {
 			sem->rspin_enabled++;
 		} else if (!taken) {
-			if  (sem->rspin_enabled > 2)
+			if  (sem->rspin_enabled > 2) {
 				sem->rspin_enabled -= 2;
-			else
+			} else if (sem->rspin_enabled) {
 				sem->rspin_enabled = 0;
+				/*
+				 * Reset wspin_cnt so that it won't get
+				 * re-enabled too soon.
+				 */
+				if (sem->wspin_cnt > -30)
+					sem->wspin_cnt = -30;
+			}
+		}
+	} else if (type == RWSEM_WAITING_FOR_WRITE) {
+		/*
+		 * Every 10 successful writer-on-writer spins more than failed
+		 * spins will increment rspin_enabled to encourage more
+		 * writer-on-reader spinning attempts.
+		 */
+		if (taken) {
+			if ((++sem->wspin_cnt >= 10) &&
+			    (sem->rspin_enabled < RWSEM_RSPIN_ENABLED_MAX)) {
+				sem->wspin_cnt = 0;
+				sem->rspin_enabled++;
+			}
+		} else if (sem->wspin_cnt > -100) {
+			sem->wspin_cnt--;
 		}
 	}
 	osq_unlock(&sem->osq);
-- 
1.7.1

[RFC PATCH-tip v4 10/10] locking/rwsem: Add a boot parameter to reader spinning threshold

[Waiman Long]

The default reader spining threshold is current set to 4096. However,
the right reader spinning threshold may vary from one system to
another and among the different architectures. This patch adds a new
kernel boot parameter to modify the threshold value. This enables
better tailoring to the needs of different systems as well as for
testing purposes.

Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
---
 Documentation/kernel-parameters.txt |    3 +++
 kernel/locking/rwsem-xadd.c         |   14 +++++++++++++-
 2 files changed, 16 insertions(+), 1 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 46c030a..90892ac 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3690,6 +3690,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
 	rw		[KNL] Mount root device read-write on boot
 
+	rwsem_rspin_threshold=
+			[KNL] Set rw semaphore reader spinning threshold
+
 	S		[KNL] Run init in single mode
 
 	s390_iommu=	[HW,S390]
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 9978159..7bb6255 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -272,6 +272,18 @@ static inline bool rwsem_try_write_lock(long count, struct rw_semaphore *sem)
 
 #ifdef CONFIG_RWSEM_SPIN_ON_OWNER
 /*
+ * Reader spinning threshold
+ */
+static int __read_mostly rspin_threshold = RWSEM_RSPIN_THRESHOLD;
+
+static int __init set_rspin_threshold(char *str)
+{
+	get_option(&str, &rspin_threshold);
+	return 0;
+}
+early_param("rwsem_rspin_threshold", set_rspin_threshold);
+
+/*
  * Try to acquire write lock before the writer has been put on wait queue.
  */
 static inline bool rwsem_try_write_lock_unqueued(struct rw_semaphore *sem)
@@ -394,7 +406,7 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem,
 	if (!osq_lock(&sem->osq))
 		goto done;
 
-	rspin_cnt = sem->rspin_enabled ? RWSEM_RSPIN_THRESHOLD : 0;
+	rspin_cnt = sem->rspin_enabled ? rspin_threshold : 0;
 
 	/*
 	 * Optimistically spin on the owner field and attempt to acquire the
-- 
1.7.1

[lkp] [locking/rwsem] INFO: rcu_preempt detected stalls on CPUs/tasks

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 3874 bytes --]


FYI, we noticed the following commit:

https://github.com/0day-ci/linux Waiman-Long/locking-rwsem-Enable-reader-optimistic-spinning/20160819-150117
commit 1802442a39b862b1adb57cbae5fbbda3945406e2 ("locking/rwsem: Add a boot parameter to reader spinning threshold")

in testcase: boot

on test machine: qemu-system-i386 -enable-kvm -cpu Haswell,+smep,+smap  -m 360M

caused below changes:


[  115.824398] INFO: rcu_preempt detected stalls on CPUs/tasks:
[  115.826472] All QSes seen, last rcu_preempt kthread activity 105002 (-184454--289456), jiffies_till_next_fqs=3, root ->qsmask 0x0
[  115.827341] sed             R running      0   296    289 0x00000008
[  115.827853]  00000000 ce7bbd2c c107a8f4 c1705803 00000000 00000128 00000121 00000008
[  115.828537]  00000384 c17b13c0 ce7bbd80 c10ce411 c16fedbc c17b1ca0 00019a2a fffd2f7a
[  115.829216]  fffb9550 00000003 00000000 c10a028d 00000383 00019a2a 00000384 0000001d
[  115.829895] Call Trace:
[  115.830092]  [<c107a8f4>] sched_show_task+0x114/0x220
[  115.830483]  [<c10ce411>] rcu_check_callbacks+0xb51/0xb60
[  115.830893]  [<c10a028d>] ? trace_hardirqs_off_caller+0xad/0x160
[  115.831348]  [<c10d56e8>] update_process_times+0x28/0x60
[  115.831756]  [<c10e6dea>] tick_periodic+0x2a/0xc0
[  115.832116]  [<c10e6fc1>] tick_handle_periodic+0x21/0x80
[  115.832554]  [<c1027b2d>] local_apic_timer_interrupt+0x2d/0x60
[  115.833000]  [<c1028116>] smp_apic_timer_interrupt+0x36/0x60
[  115.833435]  [<c150f6b6>] apic_timer_interrupt+0x36/0x40
[  115.833840]  [<c10a007b>] ? find_usage_forwards+0x5b/0x80
[  115.834251]  [<c10aa398>] ? rwsem_optimistic_spin+0x258/0x3a0
[  115.834693]  [<c150cbb2>] rwsem_down_write_failed+0x32/0x1c0
[  115.835125]  [<c118ecf0>] ? vma_adjust+0xb0/0x6c0
[  115.835490]  [<c1267779>] call_rwsem_down_write_failed+0x9/0x10
[  115.835937]  [<c150c34f>] down_write+0x4f/0x60
[  115.836277]  [<c118ecf0>] ? vma_adjust+0xb0/0x6c0
[  115.836642]  [<c118ecf0>] vma_adjust+0xb0/0x6c0
[  115.836990]  [<c118f3d9>] __split_vma+0xd9/0x180
[  115.837393]  [<c11901a2>] split_vma+0x22/0x40
[  115.837726]  [<c1192d57>] mprotect_fixup+0x1d7/0x220
[  115.838105]  [<c1192ef5>] SyS_mprotect+0x155/0x280
[  115.838474]  [<c1001e38>] do_int80_syscall_32+0x1f8/0x240
[  115.838882]  [<c150ec83>] entry_INT80_32+0x33/0x33


FYI, raw QEMU command line is:

	qemu-system-i386 -enable-kvm -cpu Haswell,+smep,+smap -kernel /pkg/linux/i386-randconfig-sb0-08201601/gcc-5/1802442a39b862b1adb57cbae5fbbda3945406e2/vmlinuz-4.8.0-rc1-00079-g1802442 -append 'ip=::::vm-vp-quantal-i386-34::dhcp root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-vp-quantal-i386-34/boot-1-quantal-core-i386.cgz-1802442a39b862b1adb57cbae5fbbda3945406e2-20160821-75698-3hybx2-6.yaml ARCH=i386 kconfig=i386-randconfig-sb0-08201601 branch=linux-devel/devel-hourly-2016082011 commit=1802442a39b862b1adb57cbae5fbbda3945406e2 BOOT_IMAGE=/pkg/linux/i386-randconfig-sb0-08201601/gcc-5/1802442a39b862b1adb57cbae5fbbda3945406e2/vmlinuz-4.8.0-rc1-00079-g1802442 max_uptime=600 RESULT_ROOT=/result/boot/1/vm-vp-quantal-i386/quantal-core-i386.cgz/i386-randconfig-sb0-08201601/gcc-5/1802442a39b862b1adb57cbae5fbbda3945406e2/6 LKP_SERVER=inn debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 systemd.log_level=err ignore_loglevel earlyprintk=ttyS0,115200 console=ttyS0,115200 console=tty0 vga=normal rw drbd.minor_count=8'  -initrd /fs/sdd1/initrd-vm-vp-quantal-i386-34 -m 360 -smp 1 -device e1000,netdev=net0 -netdev user,id=net0 -boot order=nc -no-reboot -watchdog i6300esb -watchdog-action debug -rtc base=localtime -pidfile /dev/shm/kboot/pid-vm-vp-quantal-i386-34 -serial file:/dev/shm/kboot/serial-vm-vp-quantal-i386-34 -daemonize -display none -monitor null 





Thanks,
Xiaolong

[-- Attachment #2: config-4.8.0-rc1-00079-g1802442 --]
[-- Type: text/plain, Size: 87925 bytes --]

#
# Automatically generated file; DO NOT EDIT.
# Linux/i386 4.8.0-rc1 Kernel Configuration
#
# CONFIG_64BIT is not set
CONFIG_X86_32=y
CONFIG_X86=y
CONFIG_INSTRUCTION_DECODER=y
CONFIG_OUTPUT_FORMAT="elf32-i386"
CONFIG_ARCH_DEFCONFIG="arch/x86/configs/i386_defconfig"
CONFIG_LOCKDEP_SUPPORT=y
CONFIG_STACKTRACE_SUPPORT=y
CONFIG_MMU=y
CONFIG_ARCH_MMAP_RND_BITS_MIN=8
CONFIG_ARCH_MMAP_RND_BITS_MAX=16
CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MIN=8
CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MAX=16
CONFIG_NEED_DMA_MAP_STATE=y
CONFIG_NEED_SG_DMA_LENGTH=y
CONFIG_GENERIC_ISA_DMA=y
CONFIG_GENERIC_BUG=y
CONFIG_GENERIC_HWEIGHT=y
CONFIG_ARCH_MAY_HAVE_PC_FDC=y
CONFIG_RWSEM_XCHGADD_ALGORITHM=y
CONFIG_GENERIC_CALIBRATE_DELAY=y
CONFIG_ARCH_HAS_CPU_RELAX=y
CONFIG_ARCH_HAS_CACHE_LINE_SIZE=y
CONFIG_HAVE_SETUP_PER_CPU_AREA=y
CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK=y
CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK=y
CONFIG_ARCH_HIBERNATION_POSSIBLE=y
CONFIG_ARCH_SUSPEND_POSSIBLE=y
CONFIG_ARCH_WANT_HUGE_PMD_SHARE=y
CONFIG_ARCH_WANT_GENERAL_HUGETLB=y
CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING=y
CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC=y
CONFIG_X86_32_SMP=y
CONFIG_ARCH_SUPPORTS_UPROBES=y
CONFIG_FIX_EARLYCON_MEM=y
CONFIG_DEBUG_RODATA=y
CONFIG_PGTABLE_LEVELS=3
CONFIG_DEFCONFIG_LIST="/lib/modules/$UNAME_RELEASE/.config"
CONFIG_IRQ_WORK=y
CONFIG_BUILDTIME_EXTABLE_SORT=y

#
# General setup
#
CONFIG_INIT_ENV_ARG_LIMIT=32
CONFIG_CROSS_COMPILE=""
# CONFIG_COMPILE_TEST is not set
CONFIG_LOCALVERSION=""
CONFIG_LOCALVERSION_AUTO=y
CONFIG_HAVE_KERNEL_GZIP=y
CONFIG_HAVE_KERNEL_BZIP2=y
CONFIG_HAVE_KERNEL_LZMA=y
CONFIG_HAVE_KERNEL_XZ=y
CONFIG_HAVE_KERNEL_LZO=y
CONFIG_HAVE_KERNEL_LZ4=y
# CONFIG_KERNEL_GZIP is not set
# CONFIG_KERNEL_BZIP2 is not set
CONFIG_KERNEL_LZMA=y
# CONFIG_KERNEL_XZ is not set
# CONFIG_KERNEL_LZO is not set
# CONFIG_KERNEL_LZ4 is not set
CONFIG_DEFAULT_HOSTNAME="(none)"
# CONFIG_SYSVIPC is not set
# CONFIG_POSIX_MQUEUE is not set
CONFIG_CROSS_MEMORY_ATTACH=y
CONFIG_FHANDLE=y
CONFIG_USELIB=y
# CONFIG_AUDIT is not set
CONFIG_HAVE_ARCH_AUDITSYSCALL=y

#
# IRQ subsystem
#
CONFIG_GENERIC_IRQ_PROBE=y
CONFIG_GENERIC_IRQ_SHOW=y
CONFIG_GENERIC_PENDING_IRQ=y
CONFIG_GENERIC_IRQ_CHIP=y
CONFIG_IRQ_DOMAIN=y
CONFIG_IRQ_DOMAIN_HIERARCHY=y
CONFIG_GENERIC_MSI_IRQ=y
CONFIG_GENERIC_MSI_IRQ_DOMAIN=y
CONFIG_IRQ_DOMAIN_DEBUG=y
CONFIG_IRQ_FORCED_THREADING=y
CONFIG_SPARSE_IRQ=y
CONFIG_CLOCKSOURCE_WATCHDOG=y
CONFIG_ARCH_CLOCKSOURCE_DATA=y
CONFIG_CLOCKSOURCE_VALIDATE_LAST_CYCLE=y
CONFIG_GENERIC_TIME_VSYSCALL=y
CONFIG_GENERIC_CLOCKEVENTS=y
CONFIG_GENERIC_CLOCKEVENTS_BROADCAST=y
CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST=y
CONFIG_GENERIC_CMOS_UPDATE=y

#
# Timers subsystem
#
CONFIG_HZ_PERIODIC=y
# CONFIG_NO_HZ_IDLE is not set
# CONFIG_NO_HZ is not set
# CONFIG_HIGH_RES_TIMERS is not set

#
# CPU/Task time and stats accounting
#
CONFIG_TICK_CPU_ACCOUNTING=y
CONFIG_IRQ_TIME_ACCOUNTING=y
# CONFIG_BSD_PROCESS_ACCT is not set
# CONFIG_TASKSTATS is not set

#
# RCU Subsystem
#
CONFIG_PREEMPT_RCU=y
CONFIG_RCU_EXPERT=y
CONFIG_SRCU=y
CONFIG_TASKS_RCU=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RCU_FANOUT=32
CONFIG_RCU_FANOUT_LEAF=16
CONFIG_TREE_RCU_TRACE=y
# CONFIG_RCU_BOOST is not set
CONFIG_RCU_KTHREAD_PRIO=0
CONFIG_RCU_NOCB_CPU=y
CONFIG_RCU_NOCB_CPU_NONE=y
# CONFIG_RCU_NOCB_CPU_ZERO is not set
# CONFIG_RCU_NOCB_CPU_ALL is not set
# CONFIG_RCU_EXPEDITE_BOOT is not set
CONFIG_BUILD_BIN2C=y
CONFIG_IKCONFIG=y
CONFIG_IKCONFIG_PROC=y
CONFIG_LOG_BUF_SHIFT=17
CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
CONFIG_NMI_LOG_BUF_SHIFT=13
CONFIG_HAVE_UNSTABLE_SCHED_CLOCK=y
CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH=y
CONFIG_CGROUPS=y
# CONFIG_MEMCG is not set
# CONFIG_CGROUP_SCHED is not set
# CONFIG_CGROUP_PIDS is not set
# CONFIG_CGROUP_FREEZER is not set
# CONFIG_CGROUP_HUGETLB is not set
# CONFIG_CPUSETS is not set
# CONFIG_CGROUP_DEVICE is not set
# CONFIG_CGROUP_CPUACCT is not set
# CONFIG_CGROUP_PERF is not set
# CONFIG_CGROUP_DEBUG is not set
CONFIG_CHECKPOINT_RESTORE=y
# CONFIG_NAMESPACES is not set
# CONFIG_SCHED_AUTOGROUP is not set
# CONFIG_SYSFS_DEPRECATED is not set
CONFIG_RELAY=y
CONFIG_BLK_DEV_INITRD=y
CONFIG_INITRAMFS_SOURCE=""
CONFIG_RD_GZIP=y
# CONFIG_RD_BZIP2 is not set
CONFIG_RD_LZMA=y
CONFIG_RD_XZ=y
CONFIG_RD_LZO=y
CONFIG_RD_LZ4=y
CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE=y
# CONFIG_CC_OPTIMIZE_FOR_SIZE is not set
CONFIG_ANON_INODES=y
CONFIG_HAVE_UID16=y
CONFIG_SYSCTL_EXCEPTION_TRACE=y
CONFIG_HAVE_PCSPKR_PLATFORM=y
CONFIG_BPF=y
CONFIG_EXPERT=y
CONFIG_UID16=y
CONFIG_MULTIUSER=y
# CONFIG_SGETMASK_SYSCALL is not set
CONFIG_SYSFS_SYSCALL=y
CONFIG_KALLSYMS=y
CONFIG_KALLSYMS_ALL=y
# CONFIG_KALLSYMS_ABSOLUTE_PERCPU is not set
CONFIG_KALLSYMS_BASE_RELATIVE=y
CONFIG_PRINTK=y
CONFIG_PRINTK_NMI=y
CONFIG_BUG=y
# CONFIG_PCSPKR_PLATFORM is not set
CONFIG_BASE_FULL=y
CONFIG_FUTEX=y
CONFIG_EPOLL=y
CONFIG_SIGNALFD=y
CONFIG_TIMERFD=y
CONFIG_EVENTFD=y
CONFIG_BPF_SYSCALL=y
CONFIG_SHMEM=y
# CONFIG_AIO is not set
# CONFIG_ADVISE_SYSCALLS is not set
CONFIG_USERFAULTFD=y
CONFIG_PCI_QUIRKS=y
CONFIG_MEMBARRIER=y
CONFIG_EMBEDDED=y
CONFIG_HAVE_PERF_EVENTS=y
CONFIG_PERF_USE_VMALLOC=y

#
# Kernel Performance Events And Counters
#
CONFIG_PERF_EVENTS=y
CONFIG_DEBUG_PERF_USE_VMALLOC=y
# CONFIG_VM_EVENT_COUNTERS is not set
CONFIG_COMPAT_BRK=y
CONFIG_SLAB=y
# CONFIG_SLUB is not set
# CONFIG_SLOB is not set
CONFIG_SLAB_FREELIST_RANDOM=y
# CONFIG_SYSTEM_DATA_VERIFICATION is not set
CONFIG_PROFILING=y
CONFIG_TRACEPOINTS=y
CONFIG_KEXEC_CORE=y
CONFIG_OPROFILE=y
CONFIG_OPROFILE_EVENT_MULTIPLEX=y
CONFIG_HAVE_OPROFILE=y
CONFIG_OPROFILE_NMI_TIMER=y
# CONFIG_KPROBES is not set
# CONFIG_JUMP_LABEL is not set
CONFIG_UPROBES=y
# CONFIG_HAVE_64BIT_ALIGNED_ACCESS is not set
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y
CONFIG_ARCH_USE_BUILTIN_BSWAP=y
CONFIG_HAVE_IOREMAP_PROT=y
CONFIG_HAVE_KPROBES=y
CONFIG_HAVE_KRETPROBES=y
CONFIG_HAVE_OPTPROBES=y
CONFIG_HAVE_KPROBES_ON_FTRACE=y
CONFIG_HAVE_NMI=y
CONFIG_HAVE_ARCH_TRACEHOOK=y
CONFIG_HAVE_DMA_CONTIGUOUS=y
CONFIG_GENERIC_SMP_IDLE_THREAD=y
CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT=y
CONFIG_HAVE_REGS_AND_STACK_ACCESS_API=y
CONFIG_HAVE_CLK=y
CONFIG_HAVE_DMA_API_DEBUG=y
CONFIG_HAVE_HW_BREAKPOINT=y
CONFIG_HAVE_MIXED_BREAKPOINTS_REGS=y
CONFIG_HAVE_USER_RETURN_NOTIFIER=y
CONFIG_HAVE_PERF_EVENTS_NMI=y
CONFIG_HAVE_PERF_REGS=y
CONFIG_HAVE_PERF_USER_STACK_DUMP=y
CONFIG_HAVE_ARCH_JUMP_LABEL=y
CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG=y
CONFIG_HAVE_CMPXCHG_LOCAL=y
CONFIG_HAVE_CMPXCHG_DOUBLE=y
CONFIG_ARCH_WANT_IPC_PARSE_VERSION=y
CONFIG_HAVE_ARCH_SECCOMP_FILTER=y
CONFIG_SECCOMP_FILTER=y
CONFIG_HAVE_GCC_PLUGINS=y
# CONFIG_GCC_PLUGINS is not set
CONFIG_HAVE_CC_STACKPROTECTOR=y
CONFIG_CC_STACKPROTECTOR=y
# CONFIG_CC_STACKPROTECTOR_NONE is not set
CONFIG_CC_STACKPROTECTOR_REGULAR=y
# CONFIG_CC_STACKPROTECTOR_STRONG is not set
CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES=y
CONFIG_HAVE_IRQ_TIME_ACCOUNTING=y
CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE=y
CONFIG_HAVE_ARCH_HUGE_VMAP=y
CONFIG_MODULES_USE_ELF_REL=y
CONFIG_ARCH_HAS_ELF_RANDOMIZE=y
CONFIG_HAVE_ARCH_MMAP_RND_BITS=y
CONFIG_HAVE_EXIT_THREAD=y
CONFIG_ARCH_MMAP_RND_BITS=8
CONFIG_HAVE_COPY_THREAD_TLS=y
# CONFIG_HAVE_ARCH_HASH is not set
CONFIG_ISA_BUS_API=y
CONFIG_CLONE_BACKWARDS=y
CONFIG_OLD_SIGSUSPEND3=y
CONFIG_OLD_SIGACTION=y
# CONFIG_CPU_NO_EFFICIENT_FFS is not set

#
# GCOV-based kernel profiling
#
# CONFIG_GCOV_KERNEL is not set
CONFIG_ARCH_HAS_GCOV_PROFILE_ALL=y
CONFIG_HAVE_GENERIC_DMA_COHERENT=y
CONFIG_SLABINFO=y
CONFIG_RT_MUTEXES=y
CONFIG_BASE_SMALL=0
CONFIG_MODULES=y
CONFIG_MODULE_FORCE_LOAD=y
# CONFIG_MODULE_UNLOAD is not set
# CONFIG_MODVERSIONS is not set
CONFIG_MODULE_SRCVERSION_ALL=y
# CONFIG_MODULE_SIG is not set
# CONFIG_MODULE_COMPRESS is not set
# CONFIG_TRIM_UNUSED_KSYMS is not set
CONFIG_MODULES_TREE_LOOKUP=y
# CONFIG_BLOCK is not set
CONFIG_PADATA=y
CONFIG_UNINLINE_SPIN_UNLOCK=y
CONFIG_ARCH_SUPPORTS_ATOMIC_RMW=y
CONFIG_RWSEM_SPIN_ON_OWNER=y
CONFIG_LOCK_SPIN_ON_OWNER=y
CONFIG_ARCH_USE_QUEUED_SPINLOCKS=y
CONFIG_QUEUED_SPINLOCKS=y
CONFIG_ARCH_USE_QUEUED_RWLOCKS=y
CONFIG_QUEUED_RWLOCKS=y
# CONFIG_FREEZER is not set

#
# Processor type and features
#
# CONFIG_ZONE_DMA is not set
CONFIG_SMP=y
CONFIG_X86_FEATURE_NAMES=y
# CONFIG_X86_FAST_FEATURE_TESTS is not set
# CONFIG_X86_MPPARSE is not set
CONFIG_X86_BIGSMP=y
# CONFIG_GOLDFISH is not set
# CONFIG_X86_EXTENDED_PLATFORM is not set
CONFIG_X86_INTEL_LPSS=y
CONFIG_X86_AMD_PLATFORM_DEVICE=y
CONFIG_IOSF_MBI=y
# CONFIG_IOSF_MBI_DEBUG is not set
CONFIG_X86_32_IRIS=y
# CONFIG_SCHED_OMIT_FRAME_POINTER is not set
CONFIG_HYPERVISOR_GUEST=y
CONFIG_PARAVIRT=y
# CONFIG_PARAVIRT_DEBUG is not set
# CONFIG_PARAVIRT_SPINLOCKS is not set
# CONFIG_XEN is not set
CONFIG_KVM_GUEST=y
# CONFIG_KVM_DEBUG_FS is not set
# CONFIG_LGUEST_GUEST is not set
# CONFIG_PARAVIRT_TIME_ACCOUNTING is not set
CONFIG_PARAVIRT_CLOCK=y
CONFIG_NO_BOOTMEM=y
# CONFIG_M486 is not set
# CONFIG_M586 is not set
# CONFIG_M586TSC is not set
# CONFIG_M586MMX is not set
# CONFIG_M686 is not set
# CONFIG_MPENTIUMII is not set
# CONFIG_MPENTIUMIII is not set
# CONFIG_MPENTIUMM is not set
# CONFIG_MPENTIUM4 is not set
CONFIG_MK6=y
# CONFIG_MK7 is not set
# CONFIG_MK8 is not set
# CONFIG_MCRUSOE is not set
# CONFIG_MEFFICEON is not set
# CONFIG_MWINCHIPC6 is not set
# CONFIG_MWINCHIP3D is not set
# CONFIG_MELAN is not set
# CONFIG_MGEODEGX1 is not set
# CONFIG_MGEODE_LX is not set
# CONFIG_MCYRIXIII is not set
# CONFIG_MVIAC3_2 is not set
# CONFIG_MVIAC7 is not set
# CONFIG_MCORE2 is not set
# CONFIG_MATOM is not set
# CONFIG_X86_GENERIC is not set
CONFIG_X86_INTERNODE_CACHE_SHIFT=5
CONFIG_X86_L1_CACHE_SHIFT=5
CONFIG_X86_ALIGNMENT_16=y
CONFIG_X86_USE_PPRO_CHECKSUM=y
CONFIG_X86_TSC=y
CONFIG_X86_CMPXCHG64=y
CONFIG_X86_MINIMUM_CPU_FAMILY=5
CONFIG_PROCESSOR_SELECT=y
# CONFIG_CPU_SUP_INTEL is not set
# CONFIG_CPU_SUP_CYRIX_32 is not set
CONFIG_CPU_SUP_AMD=y
# CONFIG_CPU_SUP_CENTAUR is not set
CONFIG_CPU_SUP_TRANSMETA_32=y
# CONFIG_CPU_SUP_UMC_32 is not set
CONFIG_HPET_TIMER=y
CONFIG_HPET_EMULATE_RTC=y
CONFIG_DMI=y
CONFIG_SWIOTLB=y
CONFIG_IOMMU_HELPER=y
CONFIG_NR_CPUS=32
# CONFIG_SCHED_SMT is not set
CONFIG_SCHED_MC=y
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
CONFIG_PREEMPT_COUNT=y
CONFIG_X86_LOCAL_APIC=y
CONFIG_X86_IO_APIC=y
CONFIG_X86_REROUTE_FOR_BROKEN_BOOT_IRQS=y
# CONFIG_X86_MCE is not set

#
# Performance monitoring
#
CONFIG_PERF_EVENTS_AMD_POWER=y
# CONFIG_X86_LEGACY_VM86 is not set
# CONFIG_VM86 is not set
CONFIG_TOSHIBA=y
CONFIG_I8K=y
# CONFIG_X86_REBOOTFIXUPS is not set
CONFIG_MICROCODE=y
# CONFIG_MICROCODE_INTEL is not set
# CONFIG_MICROCODE_AMD is not set
CONFIG_MICROCODE_OLD_INTERFACE=y
CONFIG_X86_MSR=m
CONFIG_X86_CPUID=m
# CONFIG_NOHIGHMEM is not set
# CONFIG_HIGHMEM4G is not set
CONFIG_HIGHMEM64G=y
CONFIG_VMSPLIT_3G=y
# CONFIG_VMSPLIT_2G is not set
# CONFIG_VMSPLIT_1G is not set
CONFIG_PAGE_OFFSET=0xC0000000
CONFIG_HIGHMEM=y
CONFIG_X86_PAE=y
CONFIG_ARCH_PHYS_ADDR_T_64BIT=y
CONFIG_ARCH_DMA_ADDR_T_64BIT=y
CONFIG_NUMA=y
# CONFIG_NUMA_EMU is not set
CONFIG_NODES_SHIFT=3
CONFIG_NEED_NODE_MEMMAP_SIZE=y
CONFIG_ARCH_DISCONTIGMEM_ENABLE=y
CONFIG_ARCH_DISCONTIGMEM_DEFAULT=y
CONFIG_ARCH_SPARSEMEM_ENABLE=y
CONFIG_ARCH_SELECT_MEMORY_MODEL=y
CONFIG_ILLEGAL_POINTER_VALUE=0
CONFIG_SELECT_MEMORY_MODEL=y
# CONFIG_DISCONTIGMEM_MANUAL is not set
CONFIG_SPARSEMEM_MANUAL=y
CONFIG_SPARSEMEM=y
CONFIG_NEED_MULTIPLE_NODES=y
CONFIG_HAVE_MEMORY_PRESENT=y
CONFIG_SPARSEMEM_STATIC=y
CONFIG_HAVE_MEMBLOCK=y
CONFIG_HAVE_MEMBLOCK_NODE_MAP=y
CONFIG_ARCH_DISCARD_MEMBLOCK=y
# CONFIG_HAVE_BOOTMEM_INFO_NODE is not set
CONFIG_MEMORY_HOTPLUG=y
CONFIG_MEMORY_HOTPLUG_SPARSE=y
CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE=y
# CONFIG_MEMORY_HOTREMOVE is not set
CONFIG_SPLIT_PTLOCK_CPUS=4
CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK=y
CONFIG_MEMORY_BALLOON=y
# CONFIG_COMPACTION is not set
CONFIG_MIGRATION=y
CONFIG_PHYS_ADDR_T_64BIT=y
CONFIG_VIRT_TO_BUS=y
# CONFIG_KSM is not set
CONFIG_DEFAULT_MMAP_MIN_ADDR=4096
# CONFIG_TRANSPARENT_HUGEPAGE is not set
# CONFIG_CLEANCACHE is not set
# CONFIG_CMA is not set
# CONFIG_ZPOOL is not set
CONFIG_ZBUD=y
CONFIG_ZSMALLOC=y
CONFIG_PGTABLE_MAPPING=y
# CONFIG_ZSMALLOC_STAT is not set
CONFIG_GENERIC_EARLY_IOREMAP=y
CONFIG_ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT=y
CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
CONFIG_IDLE_PAGE_TRACKING=y
CONFIG_FRAME_VECTOR=y
# CONFIG_HIGHPTE is not set
# CONFIG_X86_CHECK_BIOS_CORRUPTION is not set
CONFIG_X86_RESERVE_LOW=64
CONFIG_MTRR=y
# CONFIG_MTRR_SANITIZER is not set
# CONFIG_X86_PAT is not set
CONFIG_ARCH_RANDOM=y
# CONFIG_X86_SMAP is not set
CONFIG_EFI=y
CONFIG_EFI_STUB=y
CONFIG_SECCOMP=y
# CONFIG_HZ_100 is not set
# CONFIG_HZ_250 is not set
# CONFIG_HZ_300 is not set
CONFIG_HZ_1000=y
CONFIG_HZ=1000
# CONFIG_SCHED_HRTICK is not set
CONFIG_KEXEC=y
CONFIG_CRASH_DUMP=y
CONFIG_PHYSICAL_START=0x1000000
CONFIG_RELOCATABLE=y
# CONFIG_RANDOMIZE_BASE is not set
CONFIG_X86_NEED_RELOCS=y
CONFIG_PHYSICAL_ALIGN=0x200000
# CONFIG_HOTPLUG_CPU is not set
CONFIG_COMPAT_VDSO=y
# CONFIG_CMDLINE_BOOL is not set
# CONFIG_MODIFY_LDT_SYSCALL is not set
CONFIG_ARCH_ENABLE_MEMORY_HOTPLUG=y
CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE=y
CONFIG_USE_PERCPU_NUMA_NODE_ID=y

#
# Power management and ACPI options
#
# CONFIG_SUSPEND is not set
# CONFIG_PM is not set
CONFIG_ACPI=y
CONFIG_ACPI_LEGACY_TABLES_LOOKUP=y
CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC=y
CONFIG_ACPI_SYSTEM_POWER_STATES_SUPPORT=y
CONFIG_ACPI_DEBUGGER=y
CONFIG_ACPI_DEBUGGER_USER=m
CONFIG_ACPI_PROCFS_POWER=y
# CONFIG_ACPI_REV_OVERRIDE_POSSIBLE is not set
CONFIG_ACPI_EC_DEBUGFS=m
CONFIG_ACPI_AC=y
CONFIG_ACPI_BATTERY=m
# CONFIG_ACPI_BUTTON is not set
CONFIG_ACPI_VIDEO=m
CONFIG_ACPI_FAN=y
# CONFIG_ACPI_DOCK is not set
CONFIG_ACPI_CPU_FREQ_PSS=y
CONFIG_ACPI_PROCESSOR_CSTATE=y
CONFIG_ACPI_PROCESSOR_IDLE=y
CONFIG_ACPI_PROCESSOR=m
# CONFIG_ACPI_PROCESSOR_AGGREGATOR is not set
CONFIG_ACPI_THERMAL=m
CONFIG_ACPI_NUMA=y
CONFIG_ACPI_CUSTOM_DSDT_FILE=""
# CONFIG_ACPI_CUSTOM_DSDT is not set
CONFIG_ARCH_HAS_ACPI_TABLE_UPGRADE=y
CONFIG_ACPI_TABLE_UPGRADE=y
CONFIG_ACPI_DEBUG=y
CONFIG_ACPI_PCI_SLOT=y
CONFIG_X86_PM_TIMER=y
CONFIG_ACPI_CONTAINER=y
# CONFIG_ACPI_HOTPLUG_MEMORY is not set
CONFIG_ACPI_HOTPLUG_IOAPIC=y
CONFIG_ACPI_SBS=y
CONFIG_ACPI_HED=m
# CONFIG_ACPI_CUSTOM_METHOD is not set
CONFIG_ACPI_BGRT=y
CONFIG_ACPI_REDUCED_HARDWARE_ONLY=y
CONFIG_HAVE_ACPI_APEI=y
CONFIG_HAVE_ACPI_APEI_NMI=y
# CONFIG_ACPI_APEI is not set
CONFIG_DPTF_POWER=y
# CONFIG_PMIC_OPREGION is not set
# CONFIG_ACPI_CONFIGFS is not set
# CONFIG_SFI is not set

#
# CPU Frequency scaling
#
CONFIG_CPU_FREQ=y
CONFIG_CPU_FREQ_GOV_ATTR_SET=y
CONFIG_CPU_FREQ_GOV_COMMON=y
CONFIG_CPU_FREQ_STAT=y
# CONFIG_CPU_FREQ_STAT_DETAILS is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND is not set
CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE=y
# CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL is not set
CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
CONFIG_CPU_FREQ_GOV_POWERSAVE=m
CONFIG_CPU_FREQ_GOV_USERSPACE=y
# CONFIG_CPU_FREQ_GOV_ONDEMAND is not set
CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y
CONFIG_CPU_FREQ_GOV_SCHEDUTIL=m

#
# CPU frequency scaling drivers
#
# CONFIG_X86_INTEL_PSTATE is not set
CONFIG_X86_PCC_CPUFREQ=m
# CONFIG_X86_ACPI_CPUFREQ is not set
CONFIG_X86_POWERNOW_K6=m
CONFIG_X86_POWERNOW_K7=y
CONFIG_X86_GX_SUSPMOD=y
# CONFIG_X86_SPEEDSTEP_CENTRINO is not set
CONFIG_X86_SPEEDSTEP_ICH=m
# CONFIG_X86_SPEEDSTEP_SMI is not set
# CONFIG_X86_P4_CLOCKMOD is not set
# CONFIG_X86_CPUFREQ_NFORCE2 is not set
CONFIG_X86_LONGRUN=m
# CONFIG_X86_LONGHAUL is not set
# CONFIG_X86_E_POWERSAVER is not set

#
# shared options
#
CONFIG_X86_SPEEDSTEP_LIB=m
CONFIG_X86_SPEEDSTEP_RELAXED_CAP_CHECK=y

#
# CPU Idle
#
CONFIG_CPU_IDLE=y
CONFIG_CPU_IDLE_GOV_LADDER=y
# CONFIG_CPU_IDLE_GOV_MENU is not set
# CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED is not set

#
# Bus options (PCI etc.)
#
CONFIG_PCI=y
# CONFIG_PCI_GOBIOS is not set
# CONFIG_PCI_GOMMCONFIG is not set
# CONFIG_PCI_GODIRECT is not set
CONFIG_PCI_GOANY=y
CONFIG_PCI_BIOS=y
CONFIG_PCI_DIRECT=y
CONFIG_PCI_MMCONFIG=y
CONFIG_PCI_DOMAINS=y
# CONFIG_PCI_CNB20LE_QUIRK is not set
# CONFIG_PCIEPORTBUS is not set
CONFIG_PCI_BUS_ADDR_T_64BIT=y
CONFIG_PCI_MSI=y
CONFIG_PCI_MSI_IRQ_DOMAIN=y
# CONFIG_PCI_DEBUG is not set
# CONFIG_PCI_REALLOC_ENABLE_AUTO is not set
CONFIG_PCI_STUB=m
# CONFIG_HT_IRQ is not set
# CONFIG_PCI_IOV is not set
# CONFIG_PCI_PRI is not set
# CONFIG_PCI_PASID is not set
CONFIG_PCI_LABEL=y
CONFIG_HOTPLUG_PCI=y
CONFIG_HOTPLUG_PCI_COMPAQ=m
# CONFIG_HOTPLUG_PCI_COMPAQ_NVRAM is not set
CONFIG_HOTPLUG_PCI_IBM=m
# CONFIG_HOTPLUG_PCI_ACPI is not set
# CONFIG_HOTPLUG_PCI_CPCI is not set
CONFIG_HOTPLUG_PCI_SHPC=y

#
# PCI host controller drivers
#
# CONFIG_PCIE_DW_PLAT is not set
CONFIG_ISA_BUS=y
CONFIG_ISA_DMA_API=y
CONFIG_ISA=y
# CONFIG_EISA is not set
# CONFIG_SCx200 is not set
# CONFIG_ALIX is not set
# CONFIG_NET5501 is not set
# CONFIG_GEOS is not set
CONFIG_AMD_NB=y
CONFIG_PCCARD=m
CONFIG_PCMCIA=m
CONFIG_PCMCIA_LOAD_CIS=y
CONFIG_CARDBUS=y

#
# PC-card bridges
#
# CONFIG_YENTA is not set
CONFIG_PD6729=m
CONFIG_I82092=m
# CONFIG_I82365 is not set
# CONFIG_TCIC is not set
CONFIG_PCMCIA_PROBE=y
CONFIG_PCCARD_NONSTATIC=y
# CONFIG_RAPIDIO is not set
# CONFIG_X86_SYSFB is not set

#
# Executable file formats / Emulations
#
CONFIG_BINFMT_ELF=y
CONFIG_ELFCORE=y
CONFIG_BINFMT_SCRIPT=y
CONFIG_HAVE_AOUT=y
CONFIG_BINFMT_AOUT=y
# CONFIG_BINFMT_MISC is not set
# CONFIG_COREDUMP is not set
CONFIG_HAVE_ATOMIC_IOMAP=y
CONFIG_PMC_ATOM=y
CONFIG_VMD=y
CONFIG_NET=y

#
# Networking options
#
# CONFIG_PACKET is not set
CONFIG_UNIX=y
# CONFIG_UNIX_DIAG is not set
# CONFIG_NET_KEY is not set
# CONFIG_INET is not set
# CONFIG_NETWORK_SECMARK is not set
# CONFIG_NET_PTP_CLASSIFY is not set
# CONFIG_NETWORK_PHY_TIMESTAMPING is not set
# CONFIG_NETFILTER is not set
# CONFIG_ATM is not set
# CONFIG_BRIDGE is not set
# CONFIG_VLAN_8021Q is not set
# CONFIG_DECNET is not set
# CONFIG_LLC2 is not set
# CONFIG_IPX is not set
# CONFIG_ATALK is not set
# CONFIG_X25 is not set
# CONFIG_LAPB is not set
# CONFIG_PHONET is not set
# CONFIG_IEEE802154 is not set
# CONFIG_NET_SCHED is not set
# CONFIG_DCB is not set
# CONFIG_BATMAN_ADV is not set
# CONFIG_VSOCKETS is not set
# CONFIG_NETLINK_DIAG is not set
# CONFIG_MPLS is not set
# CONFIG_HSR is not set
CONFIG_RPS=y
CONFIG_RFS_ACCEL=y
CONFIG_XPS=y
# CONFIG_SOCK_CGROUP_DATA is not set
# CONFIG_CGROUP_NET_PRIO is not set
# CONFIG_CGROUP_NET_CLASSID is not set
CONFIG_NET_RX_BUSY_POLL=y
CONFIG_BQL=y
CONFIG_NET_FLOW_LIMIT=y

#
# Network testing
#
# CONFIG_HAMRADIO is not set
# CONFIG_CAN is not set
# CONFIG_IRDA is not set
# CONFIG_BT is not set
CONFIG_WIRELESS=y
# CONFIG_CFG80211 is not set
# CONFIG_LIB80211 is not set

#
# CFG80211 needs to be enabled for MAC80211
#
CONFIG_MAC80211_STA_HASH_MAX_SIZE=0
# CONFIG_WIMAX is not set
# CONFIG_RFKILL is not set
# CONFIG_NET_9P is not set
# CONFIG_CAIF is not set
# CONFIG_NFC is not set
# CONFIG_LWTUNNEL is not set
# CONFIG_DST_CACHE is not set
# CONFIG_NET_DEVLINK is not set
CONFIG_MAY_USE_DEVLINK=y

#
# Device Drivers
#

#
# Generic Driver Options
#
CONFIG_UEVENT_HELPER=y
CONFIG_UEVENT_HELPER_PATH=""
CONFIG_DEVTMPFS=y
# CONFIG_DEVTMPFS_MOUNT is not set
# CONFIG_STANDALONE is not set
CONFIG_PREVENT_FIRMWARE_BUILD=y
CONFIG_FW_LOADER=y
CONFIG_FIRMWARE_IN_KERNEL=y
CONFIG_EXTRA_FIRMWARE=""
CONFIG_FW_LOADER_USER_HELPER=y
# CONFIG_FW_LOADER_USER_HELPER_FALLBACK is not set
# CONFIG_ALLOW_DEV_COREDUMP is not set
# CONFIG_DEBUG_DRIVER is not set
CONFIG_DEBUG_DEVRES=y
# CONFIG_SYS_HYPERVISOR is not set
# CONFIG_GENERIC_CPU_DEVICES is not set
CONFIG_GENERIC_CPU_AUTOPROBE=y
CONFIG_REGMAP=y
CONFIG_REGMAP_I2C=y
CONFIG_REGMAP_SPMI=m
CONFIG_REGMAP_MMIO=y
CONFIG_REGMAP_IRQ=y
CONFIG_DMA_SHARED_BUFFER=y
# CONFIG_FENCE_TRACE is not set

#
# Bus devices
#
# CONFIG_CONNECTOR is not set
CONFIG_MTD=y
CONFIG_MTD_TESTS=m
CONFIG_MTD_REDBOOT_PARTS=y
CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK=-1
CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED=y
# CONFIG_MTD_REDBOOT_PARTS_READONLY is not set
# CONFIG_MTD_CMDLINE_PARTS is not set
# CONFIG_MTD_AR7_PARTS is not set

#
# User Modules And Translation Layers
#
# CONFIG_MTD_OOPS is not set
# CONFIG_MTD_PARTITIONED_MASTER is not set

#
# RAM/ROM/Flash chip drivers
#
CONFIG_MTD_CFI=y
CONFIG_MTD_JEDECPROBE=y
CONFIG_MTD_GEN_PROBE=y
CONFIG_MTD_CFI_ADV_OPTIONS=y
CONFIG_MTD_CFI_NOSWAP=y
# CONFIG_MTD_CFI_BE_BYTE_SWAP is not set
# CONFIG_MTD_CFI_LE_BYTE_SWAP is not set
CONFIG_MTD_CFI_GEOMETRY=y
CONFIG_MTD_MAP_BANK_WIDTH_1=y
CONFIG_MTD_MAP_BANK_WIDTH_2=y
# CONFIG_MTD_MAP_BANK_WIDTH_4 is not set
CONFIG_MTD_MAP_BANK_WIDTH_8=y
CONFIG_MTD_MAP_BANK_WIDTH_16=y
CONFIG_MTD_MAP_BANK_WIDTH_32=y
CONFIG_MTD_CFI_I1=y
CONFIG_MTD_CFI_I2=y
# CONFIG_MTD_CFI_I4 is not set
# CONFIG_MTD_CFI_I8 is not set
# CONFIG_MTD_OTP is not set
# CONFIG_MTD_CFI_INTELEXT is not set
CONFIG_MTD_CFI_AMDSTD=y
CONFIG_MTD_CFI_STAA=y
CONFIG_MTD_CFI_UTIL=y
CONFIG_MTD_RAM=y
CONFIG_MTD_ROM=y
CONFIG_MTD_ABSENT=y

#
# Mapping drivers for chip access
#
CONFIG_MTD_COMPLEX_MAPPINGS=y
# CONFIG_MTD_PHYSMAP is not set
CONFIG_MTD_AMD76XROM=m
CONFIG_MTD_ICHXROM=y
CONFIG_MTD_ESB2ROM=y
# CONFIG_MTD_CK804XROM is not set
CONFIG_MTD_SCB2_FLASH=m
# CONFIG_MTD_NETtel is not set
# CONFIG_MTD_L440GX is not set
CONFIG_MTD_PCI=m
CONFIG_MTD_PCMCIA=m
# CONFIG_MTD_PCMCIA_ANONYMOUS is not set
CONFIG_MTD_GPIO_ADDR=y
CONFIG_MTD_INTEL_VR_NOR=m
CONFIG_MTD_PLATRAM=m
CONFIG_MTD_LATCH_ADDR=m

#
# Self-contained MTD device drivers
#
CONFIG_MTD_PMC551=m
# CONFIG_MTD_PMC551_BUGFIX is not set
# CONFIG_MTD_PMC551_DEBUG is not set
CONFIG_MTD_SLRAM=y
# CONFIG_MTD_PHRAM is not set
# CONFIG_MTD_MTDRAM is not set

#
# Disk-On-Chip Device Drivers
#
CONFIG_MTD_DOCG3=m
CONFIG_BCH_CONST_M=14
CONFIG_BCH_CONST_T=4
# CONFIG_MTD_NAND is not set
CONFIG_MTD_ONENAND=y
# CONFIG_MTD_ONENAND_VERIFY_WRITE is not set
# CONFIG_MTD_ONENAND_GENERIC is not set
CONFIG_MTD_ONENAND_OTP=y
# CONFIG_MTD_ONENAND_2X_PROGRAM is not set

#
# LPDDR & LPDDR2 PCM memory drivers
#
# CONFIG_MTD_LPDDR is not set
CONFIG_MTD_SPI_NOR=y
CONFIG_MTD_MT81xx_NOR=m
CONFIG_MTD_SPI_NOR_USE_4K_SECTORS=y
CONFIG_MTD_UBI=y
CONFIG_MTD_UBI_WL_THRESHOLD=4096
CONFIG_MTD_UBI_BEB_LIMIT=20
CONFIG_MTD_UBI_FASTMAP=y
CONFIG_MTD_UBI_GLUEBI=m
# CONFIG_OF is not set
CONFIG_ARCH_MIGHT_HAVE_PC_PARPORT=y
# CONFIG_PARPORT is not set
CONFIG_PNP=y
# CONFIG_PNP_DEBUG_MESSAGES is not set

#
# Protocols
#
CONFIG_ISAPNP=y
# CONFIG_PNPBIOS is not set
CONFIG_PNPACPI=y

#
# Misc devices
#
# CONFIG_SENSORS_LIS3LV02D is not set
CONFIG_AD525X_DPOT=m
CONFIG_AD525X_DPOT_I2C=m
# CONFIG_DUMMY_IRQ is not set
# CONFIG_IBM_ASM is not set
# CONFIG_PHANTOM is not set
CONFIG_SGI_IOC4=m
# CONFIG_TIFM_CORE is not set
CONFIG_ICS932S401=m
CONFIG_ENCLOSURE_SERVICES=m
# CONFIG_CS5535_MFGPT is not set
CONFIG_HP_ILO=m
CONFIG_APDS9802ALS=m
# CONFIG_ISL29003 is not set
# CONFIG_ISL29020 is not set
CONFIG_SENSORS_TSL2550=m
# CONFIG_SENSORS_BH1780 is not set
CONFIG_SENSORS_BH1770=m
CONFIG_SENSORS_APDS990X=m
# CONFIG_HMC6352 is not set
# CONFIG_DS1682 is not set
CONFIG_BMP085=y
CONFIG_BMP085_I2C=y
# CONFIG_PCH_PHUB is not set
# CONFIG_USB_SWITCH_FSA9480 is not set
CONFIG_SRAM=y
CONFIG_C2PORT=m
# CONFIG_C2PORT_DURAMAR_2150 is not set

#
# EEPROM support
#
# CONFIG_EEPROM_AT24 is not set
CONFIG_EEPROM_LEGACY=y
CONFIG_EEPROM_MAX6875=y
CONFIG_EEPROM_93CX6=y
CONFIG_CB710_CORE=y
# CONFIG_CB710_DEBUG is not set
CONFIG_CB710_DEBUG_ASSUMPTIONS=y

#
# Texas Instruments shared transport line discipline
#
# CONFIG_TI_ST is not set
# CONFIG_SENSORS_LIS3_I2C is not set

#
# Altera FPGA firmware download module
#
CONFIG_ALTERA_STAPL=m
CONFIG_INTEL_MEI=y
CONFIG_INTEL_MEI_ME=y
# CONFIG_INTEL_MEI_TXE is not set
# CONFIG_VMWARE_VMCI is not set

#
# Intel MIC Bus Driver
#

#
# SCIF Bus Driver
#

#
# VOP Bus Driver
#

#
# Intel MIC Host Driver
#

#
# Intel MIC Card Driver
#

#
# SCIF Driver
#

#
# Intel MIC Coprocessor State Management (COSM) Drivers
#

#
# VOP Driver
#
CONFIG_ECHO=y
# CONFIG_CXL_BASE is not set
# CONFIG_CXL_AFU_DRIVER_OPS is not set
CONFIG_HAVE_IDE=y

#
# SCSI device support
#
CONFIG_SCSI_MOD=y
# CONFIG_SCSI_DMA is not set
# CONFIG_SCSI_NETLINK is not set
# CONFIG_FUSION is not set

#
# IEEE 1394 (FireWire) support
#
CONFIG_FIREWIRE=y
CONFIG_FIREWIRE_OHCI=m
CONFIG_FIREWIRE_NOSY=y
# CONFIG_MACINTOSH_DRIVERS is not set
# CONFIG_NETDEVICES is not set

#
# Input device support
#
CONFIG_INPUT=y
# CONFIG_INPUT_LEDS is not set
CONFIG_INPUT_FF_MEMLESS=m
CONFIG_INPUT_POLLDEV=m
CONFIG_INPUT_SPARSEKMAP=m
CONFIG_INPUT_MATRIXKMAP=m

#
# Userland interfaces
#
# CONFIG_INPUT_MOUSEDEV is not set
CONFIG_INPUT_JOYDEV=m
CONFIG_INPUT_EVDEV=m
# CONFIG_INPUT_EVBUG is not set

#
# Input Device Drivers
#
CONFIG_INPUT_KEYBOARD=y
CONFIG_KEYBOARD_ADP5588=m
CONFIG_KEYBOARD_ADP5589=m
CONFIG_KEYBOARD_ATKBD=y
CONFIG_KEYBOARD_QT1070=m
CONFIG_KEYBOARD_QT2160=m
CONFIG_KEYBOARD_LKKBD=m
CONFIG_KEYBOARD_GPIO=m
CONFIG_KEYBOARD_GPIO_POLLED=m
CONFIG_KEYBOARD_TCA6416=m
CONFIG_KEYBOARD_TCA8418=m
CONFIG_KEYBOARD_MATRIX=m
# CONFIG_KEYBOARD_LM8323 is not set
CONFIG_KEYBOARD_LM8333=m
# CONFIG_KEYBOARD_MAX7359 is not set
CONFIG_KEYBOARD_MCS=m
CONFIG_KEYBOARD_MPR121=m
CONFIG_KEYBOARD_NEWTON=m
# CONFIG_KEYBOARD_OPENCORES is not set
CONFIG_KEYBOARD_SAMSUNG=m
CONFIG_KEYBOARD_STOWAWAY=m
CONFIG_KEYBOARD_SUNKBD=m
CONFIG_KEYBOARD_TWL4030=m
CONFIG_KEYBOARD_XTKBD=m
CONFIG_INPUT_MOUSE=y
CONFIG_MOUSE_PS2=m
CONFIG_MOUSE_PS2_ALPS=y
CONFIG_MOUSE_PS2_BYD=y
# CONFIG_MOUSE_PS2_LOGIPS2PP is not set
CONFIG_MOUSE_PS2_SYNAPTICS=y
CONFIG_MOUSE_PS2_CYPRESS=y
# CONFIG_MOUSE_PS2_LIFEBOOK is not set
CONFIG_MOUSE_PS2_TRACKPOINT=y
CONFIG_MOUSE_PS2_ELANTECH=y
CONFIG_MOUSE_PS2_SENTELIC=y
CONFIG_MOUSE_PS2_TOUCHKIT=y
CONFIG_MOUSE_PS2_FOCALTECH=y
# CONFIG_MOUSE_PS2_VMMOUSE is not set
CONFIG_MOUSE_SERIAL=m
# CONFIG_MOUSE_APPLETOUCH is not set
# CONFIG_MOUSE_BCM5974 is not set
CONFIG_MOUSE_CYAPA=m
CONFIG_MOUSE_ELAN_I2C=m
CONFIG_MOUSE_ELAN_I2C_I2C=y
# CONFIG_MOUSE_ELAN_I2C_SMBUS is not set
CONFIG_MOUSE_INPORT=m
# CONFIG_MOUSE_ATIXL is not set
CONFIG_MOUSE_LOGIBM=m
CONFIG_MOUSE_PC110PAD=m
# CONFIG_MOUSE_VSXXXAA is not set
CONFIG_MOUSE_GPIO=m
CONFIG_MOUSE_SYNAPTICS_I2C=m
# CONFIG_MOUSE_SYNAPTICS_USB is not set
# CONFIG_INPUT_JOYSTICK is not set
CONFIG_INPUT_TABLET=y
# CONFIG_TABLET_USB_ACECAD is not set
# CONFIG_TABLET_USB_AIPTEK is not set
# CONFIG_TABLET_USB_HANWANG is not set
# CONFIG_TABLET_USB_KBTAB is not set
# CONFIG_TABLET_USB_PEGASUS is not set
CONFIG_TABLET_SERIAL_WACOM4=m
CONFIG_INPUT_TOUCHSCREEN=y
CONFIG_TOUCHSCREEN_PROPERTIES=y
# CONFIG_TOUCHSCREEN_88PM860X is not set
CONFIG_TOUCHSCREEN_AD7879=m
CONFIG_TOUCHSCREEN_AD7879_I2C=m
CONFIG_TOUCHSCREEN_ATMEL_MXT=m
# CONFIG_TOUCHSCREEN_AUO_PIXCIR is not set
CONFIG_TOUCHSCREEN_BU21013=m
# CONFIG_TOUCHSCREEN_CY8CTMG110 is not set
CONFIG_TOUCHSCREEN_CYTTSP_CORE=m
CONFIG_TOUCHSCREEN_CYTTSP_I2C=m
CONFIG_TOUCHSCREEN_CYTTSP4_CORE=m
# CONFIG_TOUCHSCREEN_CYTTSP4_I2C is not set
CONFIG_TOUCHSCREEN_DYNAPRO=m
# CONFIG_TOUCHSCREEN_HAMPSHIRE is not set
# CONFIG_TOUCHSCREEN_EETI is not set
CONFIG_TOUCHSCREEN_EGALAX_SERIAL=m
CONFIG_TOUCHSCREEN_FT6236=m
# CONFIG_TOUCHSCREEN_FUJITSU is not set
# CONFIG_TOUCHSCREEN_GOODIX is not set
# CONFIG_TOUCHSCREEN_ILI210X is not set
CONFIG_TOUCHSCREEN_GUNZE=m
CONFIG_TOUCHSCREEN_ELAN=m
CONFIG_TOUCHSCREEN_ELO=m
CONFIG_TOUCHSCREEN_WACOM_W8001=m
CONFIG_TOUCHSCREEN_WACOM_I2C=m
CONFIG_TOUCHSCREEN_MAX11801=m
CONFIG_TOUCHSCREEN_MCS5000=m
CONFIG_TOUCHSCREEN_MMS114=m
CONFIG_TOUCHSCREEN_MELFAS_MIP4=m
CONFIG_TOUCHSCREEN_MTOUCH=m
CONFIG_TOUCHSCREEN_INEXIO=m
# CONFIG_TOUCHSCREEN_MK712 is not set
# CONFIG_TOUCHSCREEN_HTCPEN is not set
# CONFIG_TOUCHSCREEN_PENMOUNT is not set
CONFIG_TOUCHSCREEN_EDT_FT5X06=m
CONFIG_TOUCHSCREEN_TOUCHRIGHT=m
# CONFIG_TOUCHSCREEN_TOUCHWIN is not set
CONFIG_TOUCHSCREEN_TI_AM335X_TSC=m
# CONFIG_TOUCHSCREEN_PIXCIR is not set
CONFIG_TOUCHSCREEN_WDT87XX_I2C=m
CONFIG_TOUCHSCREEN_WM831X=m
# CONFIG_TOUCHSCREEN_USB_COMPOSITE is not set
CONFIG_TOUCHSCREEN_TOUCHIT213=m
# CONFIG_TOUCHSCREEN_TSC_SERIO is not set
# CONFIG_TOUCHSCREEN_TSC2004 is not set
CONFIG_TOUCHSCREEN_TSC2007=m
# CONFIG_TOUCHSCREEN_RM_TS is not set
CONFIG_TOUCHSCREEN_SILEAD=m
CONFIG_TOUCHSCREEN_SIS_I2C=m
CONFIG_TOUCHSCREEN_ST1232=m
# CONFIG_TOUCHSCREEN_SX8654 is not set
CONFIG_TOUCHSCREEN_TPS6507X=m
CONFIG_TOUCHSCREEN_ZFORCE=m
# CONFIG_TOUCHSCREEN_ROHM_BU21023 is not set
CONFIG_INPUT_MISC=y
CONFIG_INPUT_88PM860X_ONKEY=m
# CONFIG_INPUT_88PM80X_ONKEY is not set
CONFIG_INPUT_AD714X=m
CONFIG_INPUT_AD714X_I2C=m
CONFIG_INPUT_BMA150=m
# CONFIG_INPUT_E3X0_BUTTON is not set
# CONFIG_INPUT_MAX77693_HAPTIC is not set
CONFIG_INPUT_MAX8925_ONKEY=m
CONFIG_INPUT_MMA8450=m
CONFIG_INPUT_MPU3050=m
# CONFIG_INPUT_APANEL is not set
CONFIG_INPUT_GP2A=m
CONFIG_INPUT_GPIO_BEEPER=m
CONFIG_INPUT_GPIO_TILT_POLLED=m
CONFIG_INPUT_WISTRON_BTNS=m
CONFIG_INPUT_ATLAS_BTNS=m
# CONFIG_INPUT_ATI_REMOTE2 is not set
# CONFIG_INPUT_KEYSPAN_REMOTE is not set
# CONFIG_INPUT_KXTJ9 is not set
# CONFIG_INPUT_POWERMATE is not set
# CONFIG_INPUT_YEALINK is not set
# CONFIG_INPUT_CM109 is not set
# CONFIG_INPUT_TPS65218_PWRBUTTON is not set
CONFIG_INPUT_TWL4030_PWRBUTTON=m
# CONFIG_INPUT_TWL4030_VIBRA is not set
CONFIG_INPUT_TWL6040_VIBRA=m
# CONFIG_INPUT_UINPUT is not set
# CONFIG_INPUT_PALMAS_PWRBUTTON is not set
CONFIG_INPUT_PCF8574=m
CONFIG_INPUT_PWM_BEEPER=m
CONFIG_INPUT_GPIO_ROTARY_ENCODER=m
CONFIG_INPUT_DA9063_ONKEY=m
CONFIG_INPUT_WM831X_ON=m
CONFIG_INPUT_ADXL34X=m
CONFIG_INPUT_ADXL34X_I2C=m
# CONFIG_INPUT_CMA3000 is not set
CONFIG_INPUT_IDEAPAD_SLIDEBAR=m
# CONFIG_INPUT_SOC_BUTTON_ARRAY is not set
# CONFIG_INPUT_DRV260X_HAPTICS is not set
CONFIG_INPUT_DRV2665_HAPTICS=m
# CONFIG_INPUT_DRV2667_HAPTICS is not set
# CONFIG_RMI4_CORE is not set

#
# Hardware I/O ports
#
CONFIG_SERIO=y
CONFIG_ARCH_MIGHT_HAVE_PC_SERIO=y
CONFIG_SERIO_I8042=y
CONFIG_SERIO_SERPORT=y
CONFIG_SERIO_CT82C710=m
CONFIG_SERIO_PCIPS2=m
CONFIG_SERIO_LIBPS2=y
# CONFIG_SERIO_RAW is not set
CONFIG_SERIO_ALTERA_PS2=m
# CONFIG_SERIO_PS2MULT is not set
# CONFIG_SERIO_ARC_PS2 is not set
CONFIG_USERIO=m
CONFIG_GAMEPORT=y
# CONFIG_GAMEPORT_NS558 is not set
CONFIG_GAMEPORT_L4=m
# CONFIG_GAMEPORT_EMU10K1 is not set
# CONFIG_GAMEPORT_FM801 is not set

#
# Character devices
#
CONFIG_TTY=y
# CONFIG_VT is not set
CONFIG_UNIX98_PTYS=y
CONFIG_LEGACY_PTYS=y
CONFIG_LEGACY_PTY_COUNT=256
# CONFIG_SERIAL_NONSTANDARD is not set
# CONFIG_NOZOMI is not set
# CONFIG_N_GSM is not set
# CONFIG_TRACE_SINK is not set
CONFIG_DEVMEM=y
# CONFIG_DEVKMEM is not set

#
# Serial drivers
#
CONFIG_SERIAL_EARLYCON=y
CONFIG_SERIAL_8250=y
CONFIG_SERIAL_8250_DEPRECATED_OPTIONS=y
CONFIG_SERIAL_8250_PNP=y
# CONFIG_SERIAL_8250_FINTEK is not set
CONFIG_SERIAL_8250_CONSOLE=y
CONFIG_SERIAL_8250_DMA=y
CONFIG_SERIAL_8250_PCI=y
# CONFIG_SERIAL_8250_CS is not set
CONFIG_SERIAL_8250_NR_UARTS=4
CONFIG_SERIAL_8250_RUNTIME_UARTS=4
# CONFIG_SERIAL_8250_EXTENDED is not set
# CONFIG_SERIAL_8250_FSL is not set
# CONFIG_SERIAL_8250_DW is not set
# CONFIG_SERIAL_8250_RT288X is not set
CONFIG_SERIAL_8250_MID=y
# CONFIG_SERIAL_8250_MOXA is not set

#
# Non-8250 serial port support
#
# CONFIG_SERIAL_UARTLITE is not set
CONFIG_SERIAL_CORE=y
CONFIG_SERIAL_CORE_CONSOLE=y
# CONFIG_SERIAL_JSM is not set
# CONFIG_SERIAL_SCCNXP is not set
# CONFIG_SERIAL_SC16IS7XX is not set
# CONFIG_SERIAL_TIMBERDALE is not set
# CONFIG_SERIAL_ALTERA_JTAGUART is not set
# CONFIG_SERIAL_ALTERA_UART is not set
# CONFIG_SERIAL_PCH_UART is not set
# CONFIG_SERIAL_ARC is not set
# CONFIG_SERIAL_RP2 is not set
# CONFIG_SERIAL_FSL_LPUART is not set
CONFIG_SERIAL_MCTRL_GPIO=y
# CONFIG_TTY_PRINTK is not set
# CONFIG_VIRTIO_CONSOLE is not set
# CONFIG_IPMI_HANDLER is not set
CONFIG_HW_RANDOM=m
CONFIG_HW_RANDOM_TIMERIOMEM=m
CONFIG_HW_RANDOM_INTEL=m
# CONFIG_HW_RANDOM_AMD is not set
CONFIG_HW_RANDOM_GEODE=m
CONFIG_HW_RANDOM_VIA=m
# CONFIG_HW_RANDOM_VIRTIO is not set
CONFIG_HW_RANDOM_TPM=m
CONFIG_NVRAM=y
# CONFIG_DTLK is not set
# CONFIG_R3964 is not set
CONFIG_APPLICOM=y
CONFIG_SONYPI=m

#
# PCMCIA character devices
#
# CONFIG_SYNCLINK_CS is not set
# CONFIG_CARDMAN_4000 is not set
CONFIG_CARDMAN_4040=m
# CONFIG_MWAVE is not set
# CONFIG_PC8736x_GPIO is not set
# CONFIG_NSC_GPIO is not set
CONFIG_HPET=y
# CONFIG_HPET_MMAP is not set
# CONFIG_HANGCHECK_TIMER is not set
CONFIG_TCG_TPM=y
CONFIG_TCG_TIS_CORE=m
CONFIG_TCG_TIS=m
CONFIG_TCG_TIS_I2C_ATMEL=y
CONFIG_TCG_TIS_I2C_INFINEON=m
CONFIG_TCG_TIS_I2C_NUVOTON=y
# CONFIG_TCG_NSC is not set
# CONFIG_TCG_ATMEL is not set
# CONFIG_TCG_INFINEON is not set
# CONFIG_TCG_CRB is not set
# CONFIG_TCG_VTPM_PROXY is not set
CONFIG_TCG_TIS_ST33ZP24=m
CONFIG_TCG_TIS_ST33ZP24_I2C=m
# CONFIG_TELCLOCK is not set
CONFIG_DEVPORT=y
CONFIG_XILLYBUS=m
CONFIG_XILLYBUS_PCIE=m

#
# I2C support
#
CONFIG_I2C=y
CONFIG_ACPI_I2C_OPREGION=y
CONFIG_I2C_BOARDINFO=y
# CONFIG_I2C_COMPAT is not set
CONFIG_I2C_CHARDEV=m
# CONFIG_I2C_MUX is not set
# CONFIG_I2C_HELPER_AUTO is not set
CONFIG_I2C_SMBUS=y

#
# I2C Algorithms
#
CONFIG_I2C_ALGOBIT=y
CONFIG_I2C_ALGOPCF=m
CONFIG_I2C_ALGOPCA=m

#
# I2C Hardware Bus support
#

#
# PC SMBus host controller drivers
#
CONFIG_I2C_ALI1535=y
CONFIG_I2C_ALI1563=m
CONFIG_I2C_ALI15X3=y
# CONFIG_I2C_AMD756 is not set
# CONFIG_I2C_AMD8111 is not set
CONFIG_I2C_I801=m
CONFIG_I2C_ISCH=m
CONFIG_I2C_ISMT=m
# CONFIG_I2C_PIIX4 is not set
CONFIG_I2C_NFORCE2=y
# CONFIG_I2C_NFORCE2_S4985 is not set
CONFIG_I2C_SIS5595=m
# CONFIG_I2C_SIS630 is not set
# CONFIG_I2C_SIS96X is not set
CONFIG_I2C_VIA=m
CONFIG_I2C_VIAPRO=y

#
# ACPI drivers
#
CONFIG_I2C_SCMI=m

#
# I2C system bus drivers (mostly embedded / system-on-chip)
#
# CONFIG_I2C_CBUS_GPIO is not set
CONFIG_I2C_DESIGNWARE_CORE=y
CONFIG_I2C_DESIGNWARE_PLATFORM=m
CONFIG_I2C_DESIGNWARE_PCI=y
CONFIG_I2C_DESIGNWARE_BAYTRAIL=y
CONFIG_I2C_EG20T=y
# CONFIG_I2C_EMEV2 is not set
CONFIG_I2C_GPIO=m
CONFIG_I2C_KEMPLD=m
CONFIG_I2C_OCORES=y
# CONFIG_I2C_PCA_PLATFORM is not set
# CONFIG_I2C_PXA_PCI is not set
CONFIG_I2C_SIMTEC=y
CONFIG_I2C_XILINX=y

#
# External I2C/SMBus adapter drivers
#
CONFIG_I2C_PARPORT_LIGHT=y
# CONFIG_I2C_TAOS_EVM is not set

#
# Other I2C/SMBus bus drivers
#
# CONFIG_I2C_PCA_ISA is not set
CONFIG_SCx200_ACB=m
CONFIG_I2C_STUB=m
CONFIG_I2C_SLAVE=y
CONFIG_I2C_SLAVE_EEPROM=m
# CONFIG_I2C_DEBUG_CORE is not set
# CONFIG_I2C_DEBUG_ALGO is not set
# CONFIG_I2C_DEBUG_BUS is not set
# CONFIG_SPI is not set
CONFIG_SPMI=m
# CONFIG_HSI is not set

#
# PPS support
#
# CONFIG_PPS is not set

#
# PPS generators support
#

#
# PTP clock support
#
# CONFIG_PTP_1588_CLOCK is not set

#
# Enable PHYLIB and NETWORK_PHY_TIMESTAMPING to see the additional clocks.
#
# CONFIG_PTP_1588_CLOCK_PCH is not set
CONFIG_PINCTRL=y

#
# Pin controllers
#
CONFIG_PINMUX=y
CONFIG_PINCONF=y
CONFIG_GENERIC_PINCONF=y
CONFIG_DEBUG_PINCTRL=y
CONFIG_PINCTRL_AMD=m
# CONFIG_PINCTRL_BAYTRAIL is not set
CONFIG_PINCTRL_CHERRYVIEW=y
CONFIG_PINCTRL_INTEL=y
CONFIG_PINCTRL_BROXTON=y
# CONFIG_PINCTRL_SUNRISEPOINT is not set
CONFIG_GPIOLIB=y
CONFIG_GPIO_DEVRES=y
CONFIG_GPIO_ACPI=y
CONFIG_GPIOLIB_IRQCHIP=y
CONFIG_DEBUG_GPIO=y
# CONFIG_GPIO_SYSFS is not set
CONFIG_GPIO_GENERIC=y

#
# Memory mapped GPIO drivers
#
CONFIG_GPIO_AMDPT=y
CONFIG_GPIO_DWAPB=y
CONFIG_GPIO_GENERIC_PLATFORM=m
CONFIG_GPIO_ICH=y
CONFIG_GPIO_LYNXPOINT=y
CONFIG_GPIO_VX855=y
# CONFIG_GPIO_ZX is not set

#
# Port-mapped I/O GPIO drivers
#
CONFIG_GPIO_104_DIO_48E=y
CONFIG_GPIO_104_IDIO_16=m
# CONFIG_GPIO_104_IDI_48 is not set
CONFIG_GPIO_F7188X=y
# CONFIG_GPIO_IT87 is not set
CONFIG_GPIO_SCH=y
CONFIG_GPIO_SCH311X=m
# CONFIG_GPIO_WS16C48 is not set

#
# I2C GPIO expanders
#
CONFIG_GPIO_ADP5588=y
# CONFIG_GPIO_ADP5588_IRQ is not set
# CONFIG_GPIO_MAX7300 is not set
CONFIG_GPIO_MAX732X=y
CONFIG_GPIO_MAX732X_IRQ=y
# CONFIG_GPIO_PCA953X is not set
CONFIG_GPIO_PCF857X=m
CONFIG_GPIO_SX150X=y
CONFIG_GPIO_TPIC2810=y

#
# MFD GPIO expanders
#
CONFIG_GPIO_ARIZONA=y
# CONFIG_GPIO_CS5535 is not set
CONFIG_GPIO_KEMPLD=m
# CONFIG_GPIO_LP3943 is not set
CONFIG_GPIO_PALMAS=y
CONFIG_GPIO_TIMBERDALE=y
CONFIG_GPIO_TPS65086=m
CONFIG_GPIO_TPS65218=m
CONFIG_GPIO_TWL4030=y
CONFIG_GPIO_TWL6040=m
CONFIG_GPIO_WM831X=m
# CONFIG_GPIO_WM8350 is not set
CONFIG_GPIO_WM8994=y

#
# PCI GPIO expanders
#
# CONFIG_GPIO_AMD8111 is not set
CONFIG_GPIO_BT8XX=m
CONFIG_GPIO_ML_IOH=m
CONFIG_GPIO_PCH=y
# CONFIG_GPIO_RDC321X is not set

#
# SPI or I2C GPIO expanders
#
CONFIG_GPIO_MCP23S08=y
CONFIG_W1=m

#
# 1-wire Bus Masters
#
CONFIG_W1_MASTER_MATROX=m
CONFIG_W1_MASTER_DS2482=m
CONFIG_W1_MASTER_DS1WM=m
CONFIG_W1_MASTER_GPIO=m

#
# 1-wire Slaves
#
# CONFIG_W1_SLAVE_THERM is not set
CONFIG_W1_SLAVE_SMEM=m
CONFIG_W1_SLAVE_DS2408=m
CONFIG_W1_SLAVE_DS2408_READBACK=y
CONFIG_W1_SLAVE_DS2413=m
# CONFIG_W1_SLAVE_DS2406 is not set
# CONFIG_W1_SLAVE_DS2423 is not set
CONFIG_W1_SLAVE_DS2431=m
CONFIG_W1_SLAVE_DS2433=m
CONFIG_W1_SLAVE_DS2433_CRC=y
CONFIG_W1_SLAVE_DS2760=m
CONFIG_W1_SLAVE_DS2780=m
CONFIG_W1_SLAVE_DS2781=m
# CONFIG_W1_SLAVE_DS28E04 is not set
CONFIG_W1_SLAVE_BQ27000=m
CONFIG_POWER_SUPPLY=y
# CONFIG_POWER_SUPPLY_DEBUG is not set
CONFIG_PDA_POWER=m
CONFIG_GENERIC_ADC_BATTERY=m
CONFIG_MAX8925_POWER=m
# CONFIG_WM831X_BACKUP is not set
CONFIG_WM831X_POWER=y
# CONFIG_WM8350_POWER is not set
CONFIG_TEST_POWER=m
CONFIG_BATTERY_88PM860X=y
# CONFIG_BATTERY_DS2760 is not set
# CONFIG_BATTERY_DS2780 is not set
CONFIG_BATTERY_DS2781=m
# CONFIG_BATTERY_DS2782 is not set
# CONFIG_BATTERY_SBS is not set
# CONFIG_BATTERY_BQ27XXX is not set
# CONFIG_BATTERY_MAX17040 is not set
CONFIG_BATTERY_MAX17042=y
# CONFIG_BATTERY_TWL4030_MADC is not set
CONFIG_CHARGER_88PM860X=m
# CONFIG_BATTERY_RX51 is not set
# CONFIG_CHARGER_MAX8903 is not set
CONFIG_CHARGER_TWL4030=m
CONFIG_CHARGER_LP8727=m
# CONFIG_CHARGER_GPIO is not set
CONFIG_CHARGER_MAX14577=m
CONFIG_CHARGER_MAX77693=m
# CONFIG_CHARGER_BQ2415X is not set
# CONFIG_CHARGER_BQ24190 is not set
# CONFIG_CHARGER_BQ24257 is not set
CONFIG_CHARGER_BQ24735=y
CONFIG_CHARGER_BQ25890=m
# CONFIG_CHARGER_SMB347 is not set
# CONFIG_CHARGER_TPS65217 is not set
CONFIG_BATTERY_GAUGE_LTC2941=m
CONFIG_CHARGER_RT9455=m
CONFIG_POWER_RESET=y
CONFIG_POWER_RESET_RESTART=y
CONFIG_POWER_AVS=y
CONFIG_HWMON=y
CONFIG_HWMON_VID=y
# CONFIG_HWMON_DEBUG_CHIP is not set

#
# Native drivers
#
# CONFIG_SENSORS_ABITUGURU is not set
CONFIG_SENSORS_ABITUGURU3=y
CONFIG_SENSORS_AD7414=m
CONFIG_SENSORS_AD7418=m
# CONFIG_SENSORS_ADM1021 is not set
CONFIG_SENSORS_ADM1025=m
CONFIG_SENSORS_ADM1026=y
# CONFIG_SENSORS_ADM1029 is not set
CONFIG_SENSORS_ADM1031=m
# CONFIG_SENSORS_ADM9240 is not set
CONFIG_SENSORS_ADT7X10=m
CONFIG_SENSORS_ADT7410=m
# CONFIG_SENSORS_ADT7411 is not set
CONFIG_SENSORS_ADT7462=m
CONFIG_SENSORS_ADT7470=m
CONFIG_SENSORS_ADT7475=y
# CONFIG_SENSORS_ASC7621 is not set
CONFIG_SENSORS_K8TEMP=y
# CONFIG_SENSORS_K10TEMP is not set
# CONFIG_SENSORS_FAM15H_POWER is not set
# CONFIG_SENSORS_APPLESMC is not set
# CONFIG_SENSORS_ASB100 is not set
CONFIG_SENSORS_ATXP1=m
# CONFIG_SENSORS_DS620 is not set
# CONFIG_SENSORS_DS1621 is not set
CONFIG_SENSORS_DELL_SMM=y
# CONFIG_SENSORS_I5K_AMB is not set
CONFIG_SENSORS_F71805F=y
CONFIG_SENSORS_F71882FG=m
CONFIG_SENSORS_F75375S=m
CONFIG_SENSORS_FSCHMD=m
CONFIG_SENSORS_GL518SM=y
CONFIG_SENSORS_GL520SM=y
CONFIG_SENSORS_G760A=y
CONFIG_SENSORS_G762=m
CONFIG_SENSORS_GPIO_FAN=y
# CONFIG_SENSORS_HIH6130 is not set
CONFIG_SENSORS_IIO_HWMON=m
CONFIG_SENSORS_I5500=y
# CONFIG_SENSORS_CORETEMP is not set
# CONFIG_SENSORS_IT87 is not set
# CONFIG_SENSORS_JC42 is not set
CONFIG_SENSORS_POWR1220=m
# CONFIG_SENSORS_LINEAGE is not set
# CONFIG_SENSORS_LTC2945 is not set
CONFIG_SENSORS_LTC2990=y
# CONFIG_SENSORS_LTC4151 is not set
# CONFIG_SENSORS_LTC4215 is not set
# CONFIG_SENSORS_LTC4222 is not set
CONFIG_SENSORS_LTC4245=y
CONFIG_SENSORS_LTC4260=m
# CONFIG_SENSORS_LTC4261 is not set
# CONFIG_SENSORS_MAX16065 is not set
CONFIG_SENSORS_MAX1619=y
# CONFIG_SENSORS_MAX1668 is not set
CONFIG_SENSORS_MAX197=m
CONFIG_SENSORS_MAX6639=m
CONFIG_SENSORS_MAX6642=y
CONFIG_SENSORS_MAX6650=m
# CONFIG_SENSORS_MAX6697 is not set
# CONFIG_SENSORS_MAX31790 is not set
CONFIG_SENSORS_MCP3021=y
CONFIG_SENSORS_LM63=m
CONFIG_SENSORS_LM73=m
CONFIG_SENSORS_LM75=m
# CONFIG_SENSORS_LM77 is not set
CONFIG_SENSORS_LM78=y
CONFIG_SENSORS_LM80=m
CONFIG_SENSORS_LM83=y
CONFIG_SENSORS_LM85=m
# CONFIG_SENSORS_LM87 is not set
CONFIG_SENSORS_LM90=y
CONFIG_SENSORS_LM92=y
# CONFIG_SENSORS_LM93 is not set
# CONFIG_SENSORS_LM95234 is not set
CONFIG_SENSORS_LM95241=m
CONFIG_SENSORS_LM95245=y
CONFIG_SENSORS_PC87360=y
CONFIG_SENSORS_PC87427=m
CONFIG_SENSORS_NTC_THERMISTOR=y
CONFIG_SENSORS_NCT6683=m
# CONFIG_SENSORS_NCT6775 is not set
CONFIG_SENSORS_NCT7802=m
# CONFIG_SENSORS_NCT7904 is not set
# CONFIG_SENSORS_PCF8591 is not set
# CONFIG_PMBUS is not set
CONFIG_SENSORS_SHT15=y
# CONFIG_SENSORS_SHT21 is not set
CONFIG_SENSORS_SHT3x=y
CONFIG_SENSORS_SHTC1=m
CONFIG_SENSORS_SIS5595=y
CONFIG_SENSORS_DME1737=m
CONFIG_SENSORS_EMC1403=m
# CONFIG_SENSORS_EMC2103 is not set
# CONFIG_SENSORS_EMC6W201 is not set
CONFIG_SENSORS_SMSC47M1=y
# CONFIG_SENSORS_SMSC47M192 is not set
CONFIG_SENSORS_SMSC47B397=m
# CONFIG_SENSORS_SCH56XX_COMMON is not set
CONFIG_SENSORS_SMM665=y
# CONFIG_SENSORS_ADC128D818 is not set
CONFIG_SENSORS_ADS1015=y
CONFIG_SENSORS_ADS7828=m
CONFIG_SENSORS_AMC6821=y
CONFIG_SENSORS_INA209=y
CONFIG_SENSORS_INA2XX=y
# CONFIG_SENSORS_INA3221 is not set
CONFIG_SENSORS_TC74=y
CONFIG_SENSORS_THMC50=m
# CONFIG_SENSORS_TMP102 is not set
CONFIG_SENSORS_TMP103=y
CONFIG_SENSORS_TMP401=y
CONFIG_SENSORS_TMP421=m
# CONFIG_SENSORS_TWL4030_MADC is not set
# CONFIG_SENSORS_VIA_CPUTEMP is not set
CONFIG_SENSORS_VIA686A=m
CONFIG_SENSORS_VT1211=m
# CONFIG_SENSORS_VT8231 is not set
# CONFIG_SENSORS_W83781D is not set
CONFIG_SENSORS_W83791D=m
CONFIG_SENSORS_W83792D=y
CONFIG_SENSORS_W83793=m
CONFIG_SENSORS_W83795=y
CONFIG_SENSORS_W83795_FANCTRL=y
CONFIG_SENSORS_W83L785TS=y
# CONFIG_SENSORS_W83L786NG is not set
# CONFIG_SENSORS_W83627HF is not set
# CONFIG_SENSORS_W83627EHF is not set
# CONFIG_SENSORS_WM831X is not set
CONFIG_SENSORS_WM8350=m

#
# ACPI drivers
#
CONFIG_SENSORS_ACPI_POWER=m
# CONFIG_SENSORS_ATK0110 is not set
CONFIG_THERMAL=y
CONFIG_THERMAL_HWMON=y
CONFIG_THERMAL_WRITABLE_TRIPS=y
# CONFIG_THERMAL_DEFAULT_GOV_STEP_WISE is not set
# CONFIG_THERMAL_DEFAULT_GOV_FAIR_SHARE is not set
CONFIG_THERMAL_DEFAULT_GOV_USER_SPACE=y
# CONFIG_THERMAL_DEFAULT_GOV_POWER_ALLOCATOR is not set
CONFIG_THERMAL_GOV_FAIR_SHARE=y
# CONFIG_THERMAL_GOV_STEP_WISE is not set
# CONFIG_THERMAL_GOV_BANG_BANG is not set
CONFIG_THERMAL_GOV_USER_SPACE=y
# CONFIG_THERMAL_GOV_POWER_ALLOCATOR is not set
CONFIG_THERMAL_EMULATION=y
CONFIG_INTEL_SOC_DTS_IOSF_CORE=y
CONFIG_INTEL_SOC_DTS_THERMAL=y

#
# ACPI INT340X thermal drivers
#
CONFIG_INT340X_THERMAL=m
CONFIG_ACPI_THERMAL_REL=m
CONFIG_INT3406_THERMAL=m
# CONFIG_INTEL_PCH_THERMAL is not set
# CONFIG_GENERIC_ADC_THERMAL is not set
# CONFIG_WATCHDOG is not set
CONFIG_SSB_POSSIBLE=y

#
# Sonics Silicon Backplane
#
# CONFIG_SSB is not set
CONFIG_BCMA_POSSIBLE=y

#
# Broadcom specific AMBA
#
CONFIG_BCMA=y
CONFIG_BCMA_HOST_PCI_POSSIBLE=y
CONFIG_BCMA_HOST_PCI=y
CONFIG_BCMA_HOST_SOC=y
CONFIG_BCMA_DRIVER_PCI=y
CONFIG_BCMA_SFLASH=y
# CONFIG_BCMA_DRIVER_GMAC_CMN is not set
CONFIG_BCMA_DRIVER_GPIO=y
# CONFIG_BCMA_DEBUG is not set

#
# Multifunction device drivers
#
CONFIG_MFD_CORE=y
CONFIG_MFD_CS5535=m
# CONFIG_MFD_AS3711 is not set
# CONFIG_PMIC_ADP5520 is not set
# CONFIG_MFD_AAT2870_CORE is not set
# CONFIG_MFD_BCM590XX is not set
# CONFIG_MFD_AXP20X_I2C is not set
# CONFIG_MFD_CROS_EC is not set
# CONFIG_PMIC_DA903X is not set
# CONFIG_MFD_DA9052_I2C is not set
# CONFIG_MFD_DA9055 is not set
CONFIG_MFD_DA9062=y
# CONFIG_MFD_DA9063 is not set
# CONFIG_MFD_DA9150 is not set
# CONFIG_MFD_MC13XXX_I2C is not set
CONFIG_HTC_PASIC3=y
# CONFIG_HTC_I2CPLD is not set
CONFIG_MFD_INTEL_QUARK_I2C_GPIO=m
CONFIG_LPC_ICH=y
CONFIG_LPC_SCH=y
# CONFIG_INTEL_SOC_PMIC is not set
CONFIG_MFD_INTEL_LPSS=m
CONFIG_MFD_INTEL_LPSS_ACPI=m
# CONFIG_MFD_INTEL_LPSS_PCI is not set
# CONFIG_MFD_JANZ_CMODIO is not set
CONFIG_MFD_KEMPLD=m
CONFIG_MFD_88PM800=m
CONFIG_MFD_88PM805=m
CONFIG_MFD_88PM860X=y
CONFIG_MFD_MAX14577=m
CONFIG_MFD_MAX77693=m
# CONFIG_MFD_MAX77843 is not set
# CONFIG_MFD_MAX8907 is not set
CONFIG_MFD_MAX8925=y
# CONFIG_MFD_MAX8997 is not set
CONFIG_MFD_MAX8998=y
CONFIG_MFD_MT6397=m
# CONFIG_MFD_MENF21BMC is not set
# CONFIG_MFD_RETU is not set
# CONFIG_MFD_PCF50633 is not set
# CONFIG_MFD_RDC321X is not set
# CONFIG_MFD_RTSX_PCI is not set
# CONFIG_MFD_RT5033 is not set
# CONFIG_MFD_RC5T583 is not set
# CONFIG_MFD_SEC_CORE is not set
# CONFIG_MFD_SI476X_CORE is not set
CONFIG_MFD_SM501=m
CONFIG_MFD_SM501_GPIO=y
# CONFIG_MFD_SKY81452 is not set
# CONFIG_MFD_SMSC is not set
# CONFIG_ABX500_CORE is not set
CONFIG_MFD_SYSCON=y
CONFIG_MFD_TI_AM335X_TSCADC=y
CONFIG_MFD_LP3943=m
# CONFIG_MFD_LP8788 is not set
CONFIG_MFD_PALMAS=y
# CONFIG_TPS6105X is not set
# CONFIG_TPS65010 is not set
# CONFIG_TPS6507X is not set
CONFIG_MFD_TPS65086=y
# CONFIG_MFD_TPS65090 is not set
CONFIG_MFD_TPS65217=m
CONFIG_MFD_TPS65218=y
# CONFIG_MFD_TPS6586X is not set
# CONFIG_MFD_TPS65910 is not set
# CONFIG_MFD_TPS65912_I2C is not set
# CONFIG_MFD_TPS80031 is not set
CONFIG_TWL4030_CORE=y
CONFIG_MFD_TWL4030_AUDIO=y
CONFIG_TWL6040_CORE=y
# CONFIG_MFD_WL1273_CORE is not set
CONFIG_MFD_LM3533=y
CONFIG_MFD_TIMBERDALE=m
# CONFIG_MFD_TMIO is not set
CONFIG_MFD_VX855=y
CONFIG_MFD_ARIZONA=y
CONFIG_MFD_ARIZONA_I2C=y
CONFIG_MFD_CS47L24=y
CONFIG_MFD_WM5102=y
# CONFIG_MFD_WM5110 is not set
CONFIG_MFD_WM8997=y
# CONFIG_MFD_WM8998 is not set
# CONFIG_MFD_WM8400 is not set
CONFIG_MFD_WM831X=y
CONFIG_MFD_WM831X_I2C=y
CONFIG_MFD_WM8350=y
CONFIG_MFD_WM8350_I2C=y
CONFIG_MFD_WM8994=y
# CONFIG_REGULATOR is not set
CONFIG_MEDIA_SUPPORT=m

#
# Multimedia core support
#
# CONFIG_MEDIA_CAMERA_SUPPORT is not set
CONFIG_MEDIA_ANALOG_TV_SUPPORT=y
CONFIG_MEDIA_DIGITAL_TV_SUPPORT=y
# CONFIG_MEDIA_RADIO_SUPPORT is not set
# CONFIG_MEDIA_SDR_SUPPORT is not set
# CONFIG_MEDIA_RC_SUPPORT is not set
CONFIG_MEDIA_CEC_EDID=y
CONFIG_MEDIA_CONTROLLER=y
# CONFIG_MEDIA_CONTROLLER_DVB is not set
CONFIG_VIDEO_DEV=m
CONFIG_VIDEO_V4L2_SUBDEV_API=y
CONFIG_VIDEO_V4L2=m
# CONFIG_VIDEO_ADV_DEBUG is not set
CONFIG_VIDEO_FIXED_MINOR_RANGES=y
CONFIG_VIDEO_TUNER=m
CONFIG_V4L2_FLASH_LED_CLASS=m
CONFIG_VIDEOBUF_GEN=m
CONFIG_VIDEOBUF_DMA_SG=m
CONFIG_VIDEOBUF2_CORE=m
CONFIG_VIDEOBUF2_MEMOPS=m
CONFIG_VIDEOBUF2_DMA_SG=m
CONFIG_DVB_CORE=m
CONFIG_TTPCI_EEPROM=m
CONFIG_DVB_MAX_ADAPTERS=8
CONFIG_DVB_DYNAMIC_MINORS=y

#
# Media drivers
#
CONFIG_MEDIA_PCI_SUPPORT=y

#
# Media capture/analog TV support
#
CONFIG_VIDEO_HEXIUM_GEMINI=m
CONFIG_VIDEO_HEXIUM_ORION=m
CONFIG_VIDEO_MXB=m
# CONFIG_VIDEO_DT3155 is not set

#
# Media capture/analog/hybrid TV support
#
# CONFIG_VIDEO_CX25821 is not set
CONFIG_VIDEO_SAA7134=m
# CONFIG_VIDEO_SAA7134_DVB is not set
# CONFIG_VIDEO_SAA7164 is not set

#
# Media digital TV PCI Adapters
#
CONFIG_DVB_AV7110_IR=y
CONFIG_DVB_AV7110=m
# CONFIG_DVB_AV7110_OSD is not set
# CONFIG_DVB_BUDGET_CORE is not set
# CONFIG_DVB_B2C2_FLEXCOP_PCI is not set
# CONFIG_DVB_PLUTO2 is not set
CONFIG_DVB_PT1=m
CONFIG_DVB_PT3=m
# CONFIG_DVB_NGENE is not set
CONFIG_DVB_DDBRIDGE=m
CONFIG_DVB_PLATFORM_DRIVERS=y

#
# Supported MMC/SDIO adapters
#
CONFIG_SMS_SDIO_DRV=m

#
# Supported FireWire (IEEE 1394) Adapters
#
# CONFIG_DVB_FIREDTV is not set
CONFIG_MEDIA_COMMON_OPTIONS=y

#
# common driver options
#
CONFIG_VIDEO_TVEEPROM=m
CONFIG_VIDEO_SAA7146=m
CONFIG_VIDEO_SAA7146_VV=m
CONFIG_SMS_SIANO_MDTV=m

#
# Media ancillary drivers (tuners, sensors, i2c, frontends)
#
# CONFIG_MEDIA_SUBDRV_AUTOSELECT is not set
CONFIG_MEDIA_ATTACH=y

#
# Encoders, decoders, sensors and other helper chips
#

#
# Audio decoders, processors and mixers
#
CONFIG_VIDEO_TVAUDIO=m
# CONFIG_VIDEO_TDA7432 is not set
CONFIG_VIDEO_TDA9840=m
# CONFIG_VIDEO_TEA6415C is not set
CONFIG_VIDEO_TEA6420=m
# CONFIG_VIDEO_MSP3400 is not set
CONFIG_VIDEO_CS3308=m
# CONFIG_VIDEO_CS5345 is not set
CONFIG_VIDEO_CS53L32A=m
CONFIG_VIDEO_TLV320AIC23B=m
CONFIG_VIDEO_UDA1342=m
CONFIG_VIDEO_WM8775=m
# CONFIG_VIDEO_WM8739 is not set
# CONFIG_VIDEO_VP27SMPX is not set
CONFIG_VIDEO_SONY_BTF_MPX=m

#
# RDS decoders
#
CONFIG_VIDEO_SAA6588=m

#
# Video decoders
#
CONFIG_VIDEO_ADV7180=m
# CONFIG_VIDEO_ADV7183 is not set
CONFIG_VIDEO_ADV7604=m
# CONFIG_VIDEO_ADV7842 is not set
CONFIG_VIDEO_BT819=m
# CONFIG_VIDEO_BT856 is not set
CONFIG_VIDEO_BT866=m
# CONFIG_VIDEO_KS0127 is not set
CONFIG_VIDEO_ML86V7667=m
CONFIG_VIDEO_SAA7110=m
# CONFIG_VIDEO_SAA711X is not set
CONFIG_VIDEO_TC358743=m
CONFIG_VIDEO_TVP514X=m
# CONFIG_VIDEO_TVP5150 is not set
CONFIG_VIDEO_TVP7002=m
CONFIG_VIDEO_TW2804=m
# CONFIG_VIDEO_TW9903 is not set
# CONFIG_VIDEO_TW9906 is not set
CONFIG_VIDEO_VPX3220=m

#
# Video and audio decoders
#
# CONFIG_VIDEO_SAA717X is not set
CONFIG_VIDEO_CX25840=m

#
# Video encoders
#
CONFIG_VIDEO_SAA7127=m
CONFIG_VIDEO_SAA7185=m
# CONFIG_VIDEO_ADV7170 is not set
CONFIG_VIDEO_ADV7175=m
CONFIG_VIDEO_ADV7343=m
CONFIG_VIDEO_ADV7393=m
CONFIG_VIDEO_ADV7511=m
CONFIG_VIDEO_AD9389B=m
CONFIG_VIDEO_AK881X=m
CONFIG_VIDEO_THS8200=m

#
# Camera sensor devices
#
# CONFIG_VIDEO_OV9650 is not set
CONFIG_VIDEO_S5K4ECGX=m
CONFIG_VIDEO_S5K5BAF=m

#
# Flash devices
#

#
# Video improvement chips
#
CONFIG_VIDEO_UPD64031A=m
CONFIG_VIDEO_UPD64083=m

#
# Audio/Video compression chips
#
CONFIG_VIDEO_SAA6752HS=m

#
# Miscellaneous helper chips
#
CONFIG_VIDEO_THS7303=m
# CONFIG_VIDEO_M52790 is not set

#
# Sensors used on soc_camera driver
#
CONFIG_MEDIA_TUNER=m

#
# Customize TV tuners
#
CONFIG_MEDIA_TUNER_SIMPLE=m
CONFIG_MEDIA_TUNER_TDA8290=m
CONFIG_MEDIA_TUNER_TDA827X=m
CONFIG_MEDIA_TUNER_TDA18271=m
CONFIG_MEDIA_TUNER_TDA9887=m
# CONFIG_MEDIA_TUNER_TEA5761 is not set
CONFIG_MEDIA_TUNER_TEA5767=m
CONFIG_MEDIA_TUNER_MT20XX=m
# CONFIG_MEDIA_TUNER_MT2060 is not set
CONFIG_MEDIA_TUNER_MT2063=m
CONFIG_MEDIA_TUNER_MT2266=m
CONFIG_MEDIA_TUNER_MT2131=m
CONFIG_MEDIA_TUNER_QT1010=m
CONFIG_MEDIA_TUNER_XC2028=m
CONFIG_MEDIA_TUNER_XC5000=m
CONFIG_MEDIA_TUNER_XC4000=m
CONFIG_MEDIA_TUNER_MXL5005S=m
# CONFIG_MEDIA_TUNER_MXL5007T is not set
CONFIG_MEDIA_TUNER_MC44S803=m
CONFIG_MEDIA_TUNER_MAX2165=m
# CONFIG_MEDIA_TUNER_TDA18218 is not set
# CONFIG_MEDIA_TUNER_FC0011 is not set
# CONFIG_MEDIA_TUNER_FC0012 is not set
CONFIG_MEDIA_TUNER_FC0013=m
# CONFIG_MEDIA_TUNER_TDA18212 is not set
# CONFIG_MEDIA_TUNER_E4000 is not set
CONFIG_MEDIA_TUNER_FC2580=m
CONFIG_MEDIA_TUNER_M88RS6000T=m
CONFIG_MEDIA_TUNER_TUA9001=m
# CONFIG_MEDIA_TUNER_SI2157 is not set
CONFIG_MEDIA_TUNER_IT913X=m
CONFIG_MEDIA_TUNER_R820T=m
CONFIG_MEDIA_TUNER_MXL301RF=m
CONFIG_MEDIA_TUNER_QM1D1C0042=m

#
# Customise DVB Frontends
#

#
# Multistandard (satellite) frontends
#
CONFIG_DVB_STB0899=m
CONFIG_DVB_STB6100=m
CONFIG_DVB_STV090x=m
CONFIG_DVB_STV6110x=m

#
# Multistandard (cable + terrestrial) frontends
#
CONFIG_DVB_DRXK=m
CONFIG_DVB_TDA18271C2DD=m
CONFIG_DVB_SI2165=m
# CONFIG_DVB_MN88472 is not set
CONFIG_DVB_MN88473=m

#
# DVB-S (satellite) frontends
#
CONFIG_DVB_CX24110=m
CONFIG_DVB_CX24123=m
# CONFIG_DVB_MT312 is not set
CONFIG_DVB_ZL10036=m
CONFIG_DVB_ZL10039=m
CONFIG_DVB_S5H1420=m
CONFIG_DVB_STV0288=m
CONFIG_DVB_STB6000=m
CONFIG_DVB_STV0299=m
# CONFIG_DVB_STV6110 is not set
CONFIG_DVB_STV0900=m
CONFIG_DVB_TDA8083=m
CONFIG_DVB_TDA10086=m
# CONFIG_DVB_TDA8261 is not set
# CONFIG_DVB_VES1X93 is not set
CONFIG_DVB_TUNER_ITD1000=m
# CONFIG_DVB_TUNER_CX24113 is not set
# CONFIG_DVB_TDA826X is not set
# CONFIG_DVB_TUA6100 is not set
# CONFIG_DVB_CX24116 is not set
# CONFIG_DVB_CX24117 is not set
CONFIG_DVB_CX24120=m
CONFIG_DVB_SI21XX=m
CONFIG_DVB_TS2020=m
CONFIG_DVB_DS3000=m
CONFIG_DVB_MB86A16=m
CONFIG_DVB_TDA10071=m

#
# DVB-T (terrestrial) frontends
#
CONFIG_DVB_SP8870=m
CONFIG_DVB_SP887X=m
CONFIG_DVB_CX22700=m
# CONFIG_DVB_CX22702 is not set
# CONFIG_DVB_S5H1432 is not set
CONFIG_DVB_DRXD=m
CONFIG_DVB_L64781=m
CONFIG_DVB_TDA1004X=m
CONFIG_DVB_NXT6000=m
CONFIG_DVB_MT352=m
CONFIG_DVB_ZL10353=m
CONFIG_DVB_DIB3000MB=m
CONFIG_DVB_DIB3000MC=m
CONFIG_DVB_DIB7000M=m
CONFIG_DVB_DIB7000P=m
CONFIG_DVB_DIB9000=m
CONFIG_DVB_TDA10048=m
# CONFIG_DVB_AF9013 is not set
CONFIG_DVB_EC100=m
CONFIG_DVB_HD29L2=m
# CONFIG_DVB_STV0367 is not set
# CONFIG_DVB_CXD2820R is not set
CONFIG_DVB_CXD2841ER=m
# CONFIG_DVB_AS102_FE is not set

#
# DVB-C (cable) frontends
#
CONFIG_DVB_VES1820=m
CONFIG_DVB_TDA10021=m
# CONFIG_DVB_TDA10023 is not set
# CONFIG_DVB_STV0297 is not set

#
# ATSC (North American/Korean Terrestrial/Cable DTV) frontends
#
CONFIG_DVB_NXT200X=m
# CONFIG_DVB_OR51211 is not set
CONFIG_DVB_OR51132=m
CONFIG_DVB_BCM3510=m
CONFIG_DVB_LGDT330X=m
CONFIG_DVB_LGDT3305=m
CONFIG_DVB_LGDT3306A=m
CONFIG_DVB_LG2160=m
# CONFIG_DVB_S5H1409 is not set
CONFIG_DVB_AU8522=m
CONFIG_DVB_AU8522_DTV=m
CONFIG_DVB_AU8522_V4L=m
CONFIG_DVB_S5H1411=m

#
# ISDB-T (terrestrial) frontends
#
CONFIG_DVB_S921=m
CONFIG_DVB_DIB8000=m
# CONFIG_DVB_MB86A20S is not set

#
# ISDB-S (satellite) & ISDB-T (terrestrial) frontends
#
# CONFIG_DVB_TC90522 is not set

#
# Digital terrestrial only tuners/PLL
#
CONFIG_DVB_PLL=m
CONFIG_DVB_TUNER_DIB0070=m
# CONFIG_DVB_TUNER_DIB0090 is not set

#
# SEC control devices for DVB-S
#
# CONFIG_DVB_DRX39XYJ is not set
# CONFIG_DVB_LNBH25 is not set
CONFIG_DVB_LNBP21=m
CONFIG_DVB_LNBP22=m
CONFIG_DVB_ISL6405=m
CONFIG_DVB_ISL6421=m
CONFIG_DVB_ISL6423=m
# CONFIG_DVB_A8293 is not set
# CONFIG_DVB_SP2 is not set
CONFIG_DVB_LGS8GL5=m
# CONFIG_DVB_LGS8GXX is not set
# CONFIG_DVB_ATBM8830 is not set
# CONFIG_DVB_TDA665x is not set
CONFIG_DVB_IX2505V=m
CONFIG_DVB_M88RS2000=m
CONFIG_DVB_AF9033=m
# CONFIG_DVB_HORUS3A is not set
# CONFIG_DVB_ASCOT2E is not set
CONFIG_DVB_HELENE=m

#
# Tools to develop new frontends
#
# CONFIG_DVB_DUMMY_FE is not set

#
# Graphics support
#
CONFIG_AGP=m
# CONFIG_AGP_ALI is not set
CONFIG_AGP_ATI=m
CONFIG_AGP_AMD=m
# CONFIG_AGP_AMD64 is not set
# CONFIG_AGP_INTEL is not set
CONFIG_AGP_NVIDIA=m
# CONFIG_AGP_SIS is not set
CONFIG_AGP_SWORKS=m
CONFIG_AGP_VIA=m
# CONFIG_AGP_EFFICEON is not set
CONFIG_VGA_ARB=y
CONFIG_VGA_ARB_MAX_GPUS=16
CONFIG_VGA_SWITCHEROO=y
# CONFIG_DRM is not set

#
# ACP (Audio CoProcessor) Configuration
#

#
# Frame buffer Devices
#
CONFIG_FB=y
CONFIG_FIRMWARE_EDID=y
CONFIG_FB_CMDLINE=y
CONFIG_FB_NOTIFY=y
CONFIG_FB_DDC=y
# CONFIG_FB_BOOT_VESA_SUPPORT is not set
CONFIG_FB_CFB_FILLRECT=y
CONFIG_FB_CFB_COPYAREA=y
CONFIG_FB_CFB_IMAGEBLIT=y
# CONFIG_FB_CFB_REV_PIXELS_IN_BYTE is not set
CONFIG_FB_SYS_FILLRECT=m
CONFIG_FB_SYS_COPYAREA=m
CONFIG_FB_SYS_IMAGEBLIT=m
CONFIG_FB_FOREIGN_ENDIAN=y
CONFIG_FB_BOTH_ENDIAN=y
# CONFIG_FB_BIG_ENDIAN is not set
# CONFIG_FB_LITTLE_ENDIAN is not set
CONFIG_FB_SYS_FOPS=m
CONFIG_FB_DEFERRED_IO=y
CONFIG_FB_HECUBA=m
CONFIG_FB_SVGALIB=y
# CONFIG_FB_MACMODES is not set
CONFIG_FB_BACKLIGHT=y
CONFIG_FB_MODE_HELPERS=y
CONFIG_FB_TILEBLITTING=y

#
# Frame buffer hardware drivers
#
# CONFIG_FB_CIRRUS is not set
CONFIG_FB_PM2=m
CONFIG_FB_PM2_FIFO_DISCONNECT=y
# CONFIG_FB_CYBER2000 is not set
# CONFIG_FB_ARC is not set
CONFIG_FB_ASILIANT=y
CONFIG_FB_IMSTT=y
# CONFIG_FB_VGA16 is not set
# CONFIG_FB_VESA is not set
CONFIG_FB_EFI=y
CONFIG_FB_N411=m
CONFIG_FB_HGA=m
CONFIG_FB_OPENCORES=y
# CONFIG_FB_S1D13XXX is not set
CONFIG_FB_NVIDIA=m
CONFIG_FB_NVIDIA_I2C=y
CONFIG_FB_NVIDIA_DEBUG=y
# CONFIG_FB_NVIDIA_BACKLIGHT is not set
# CONFIG_FB_RIVA is not set
CONFIG_FB_I740=y
CONFIG_FB_LE80578=y
CONFIG_FB_CARILLO_RANCH=y
CONFIG_FB_MATROX=m
# CONFIG_FB_MATROX_MILLENIUM is not set
CONFIG_FB_MATROX_MYSTIQUE=y
# CONFIG_FB_MATROX_G is not set
CONFIG_FB_MATROX_I2C=m
# CONFIG_FB_RADEON is not set
CONFIG_FB_ATY128=m
CONFIG_FB_ATY128_BACKLIGHT=y
CONFIG_FB_ATY=y
# CONFIG_FB_ATY_CT is not set
# CONFIG_FB_ATY_GX is not set
CONFIG_FB_ATY_BACKLIGHT=y
CONFIG_FB_S3=m
CONFIG_FB_S3_DDC=y
CONFIG_FB_SAVAGE=y
# CONFIG_FB_SAVAGE_I2C is not set
CONFIG_FB_SAVAGE_ACCEL=y
# CONFIG_FB_SIS is not set
# CONFIG_FB_VIA is not set
# CONFIG_FB_NEOMAGIC is not set
CONFIG_FB_KYRO=y
CONFIG_FB_3DFX=m
CONFIG_FB_3DFX_ACCEL=y
# CONFIG_FB_3DFX_I2C is not set
# CONFIG_FB_VOODOO1 is not set
CONFIG_FB_VT8623=y
# CONFIG_FB_TRIDENT is not set
# CONFIG_FB_ARK is not set
# CONFIG_FB_PM3 is not set
CONFIG_FB_CARMINE=y
CONFIG_FB_CARMINE_DRAM_EVAL=y
# CONFIG_CARMINE_DRAM_CUSTOM is not set
CONFIG_FB_GEODE=y
# CONFIG_FB_GEODE_LX is not set
CONFIG_FB_GEODE_GX=m
CONFIG_FB_GEODE_GX1=y
CONFIG_FB_SM501=m
CONFIG_FB_IBM_GXT4500=y
CONFIG_FB_VIRTUAL=m
# CONFIG_FB_METRONOME is not set
# CONFIG_FB_MB862XX is not set
# CONFIG_FB_BROADSHEET is not set
# CONFIG_FB_AUO_K190X is not set
CONFIG_FB_SIMPLE=y
CONFIG_FB_SM712=m
CONFIG_BACKLIGHT_LCD_SUPPORT=y
CONFIG_LCD_CLASS_DEVICE=y
CONFIG_LCD_PLATFORM=m
CONFIG_BACKLIGHT_CLASS_DEVICE=y
CONFIG_BACKLIGHT_GENERIC=m
CONFIG_BACKLIGHT_LM3533=y
CONFIG_BACKLIGHT_CARILLO_RANCH=y
# CONFIG_BACKLIGHT_PWM is not set
CONFIG_BACKLIGHT_MAX8925=m
CONFIG_BACKLIGHT_APPLE=y
# CONFIG_BACKLIGHT_PM8941_WLED is not set
CONFIG_BACKLIGHT_SAHARA=m
CONFIG_BACKLIGHT_WM831X=m
CONFIG_BACKLIGHT_ADP8860=y
CONFIG_BACKLIGHT_ADP8870=m
CONFIG_BACKLIGHT_88PM860X=y
# CONFIG_BACKLIGHT_LM3630A is not set
CONFIG_BACKLIGHT_LM3639=y
CONFIG_BACKLIGHT_LP855X=y
# CONFIG_BACKLIGHT_PANDORA is not set
# CONFIG_BACKLIGHT_TPS65217 is not set
CONFIG_BACKLIGHT_GPIO=m
# CONFIG_BACKLIGHT_LV5207LP is not set
# CONFIG_BACKLIGHT_BD6107 is not set
CONFIG_VGASTATE=y
CONFIG_HDMI=y
# CONFIG_LOGO is not set
# CONFIG_SOUND is not set

#
# HID support
#
CONFIG_HID=m
# CONFIG_HID_BATTERY_STRENGTH is not set
CONFIG_HIDRAW=y
CONFIG_UHID=m
# CONFIG_HID_GENERIC is not set

#
# Special HID drivers
#
CONFIG_HID_A4TECH=m
CONFIG_HID_ACRUX=m
CONFIG_HID_ACRUX_FF=y
CONFIG_HID_APPLE=m
CONFIG_HID_AUREAL=m
CONFIG_HID_BELKIN=m
# CONFIG_HID_CHERRY is not set
CONFIG_HID_CHICONY=m
CONFIG_HID_CMEDIA=m
CONFIG_HID_CYPRESS=m
CONFIG_HID_DRAGONRISE=m
CONFIG_DRAGONRISE_FF=y
# CONFIG_HID_EMS_FF is not set
CONFIG_HID_ELECOM=m
CONFIG_HID_EZKEY=m
CONFIG_HID_GEMBIRD=m
CONFIG_HID_GFRM=m
CONFIG_HID_KEYTOUCH=m
CONFIG_HID_KYE=m
CONFIG_HID_WALTOP=m
CONFIG_HID_GYRATION=m
# CONFIG_HID_ICADE is not set
CONFIG_HID_TWINHAN=m
# CONFIG_HID_KENSINGTON is not set
CONFIG_HID_LCPOWER=m
# CONFIG_HID_LED is not set
CONFIG_HID_LENOVO=m
CONFIG_HID_LOGITECH=m
CONFIG_HID_LOGITECH_DJ=m
CONFIG_HID_LOGITECH_HIDPP=m
CONFIG_LOGITECH_FF=y
CONFIG_LOGIRUMBLEPAD2_FF=y
CONFIG_LOGIG940_FF=y
CONFIG_LOGIWHEELS_FF=y
# CONFIG_HID_MAGICMOUSE is not set
CONFIG_HID_MICROSOFT=m
# CONFIG_HID_MONTEREY is not set
CONFIG_HID_MULTITOUCH=m
# CONFIG_HID_ORTEK is not set
# CONFIG_HID_PANTHERLORD is not set
CONFIG_HID_PETALYNX=m
# CONFIG_HID_PICOLCD is not set
CONFIG_HID_PLANTRONICS=m
# CONFIG_HID_PRIMAX is not set
CONFIG_HID_SAITEK=m
CONFIG_HID_SAMSUNG=m
CONFIG_HID_SPEEDLINK=m
# CONFIG_HID_STEELSERIES is not set
# CONFIG_HID_SUNPLUS is not set
CONFIG_HID_RMI=m
# CONFIG_HID_GREENASIA is not set
# CONFIG_HID_SMARTJOYPLUS is not set
# CONFIG_HID_TIVO is not set
CONFIG_HID_TOPSEED=m
# CONFIG_HID_THINGM is not set
CONFIG_HID_THRUSTMASTER=m
# CONFIG_THRUSTMASTER_FF is not set
CONFIG_HID_WACOM=m
# CONFIG_HID_WIIMOTE is not set
CONFIG_HID_XINMO=m
CONFIG_HID_ZEROPLUS=m
CONFIG_ZEROPLUS_FF=y
CONFIG_HID_ZYDACRON=m
# CONFIG_HID_SENSOR_HUB is not set
CONFIG_HID_ALPS=m

#
# I2C HID support
#
# CONFIG_I2C_HID is not set
CONFIG_USB_OHCI_LITTLE_ENDIAN=y
CONFIG_USB_SUPPORT=y
CONFIG_USB_ARCH_HAS_HCD=y
# CONFIG_USB is not set

#
# USB port drivers
#

#
# USB Physical Layer drivers
#
# CONFIG_USB_PHY is not set
# CONFIG_NOP_USB_XCEIV is not set
# CONFIG_USB_GPIO_VBUS is not set
# CONFIG_USB_GADGET is not set
CONFIG_UWB=y
CONFIG_UWB_WHCI=y
CONFIG_MMC=y
CONFIG_MMC_DEBUG=y

#
# MMC/SD/SDIO Card Drivers
#
# CONFIG_SDIO_UART is not set
CONFIG_MMC_TEST=m

#
# MMC/SD/SDIO Host Controller Drivers
#
CONFIG_MMC_SDHCI=m
CONFIG_MMC_SDHCI_PCI=m
CONFIG_MMC_RICOH_MMC=y
CONFIG_MMC_SDHCI_ACPI=m
CONFIG_MMC_SDHCI_PLTFM=m
# CONFIG_MMC_WBSD is not set
# CONFIG_MMC_TIFM_SD is not set
# CONFIG_MMC_SDRICOH_CS is not set
CONFIG_MMC_CB710=m
# CONFIG_MMC_VIA_SDMMC is not set
CONFIG_MMC_USDHI6ROL0=m
CONFIG_MMC_TOSHIBA_PCI=m
# CONFIG_MMC_MTK is not set
# CONFIG_MEMSTICK is not set
CONFIG_NEW_LEDS=y
CONFIG_LEDS_CLASS=y
CONFIG_LEDS_CLASS_FLASH=m

#
# LED drivers
#
CONFIG_LEDS_88PM860X=y
# CONFIG_LEDS_LM3530 is not set
# CONFIG_LEDS_LM3533 is not set
CONFIG_LEDS_LM3642=y
# CONFIG_LEDS_PCA9532 is not set
# CONFIG_LEDS_GPIO is not set
# CONFIG_LEDS_LP3944 is not set
CONFIG_LEDS_LP3952=m
CONFIG_LEDS_LP55XX_COMMON=y
CONFIG_LEDS_LP5521=y
# CONFIG_LEDS_LP5523 is not set
CONFIG_LEDS_LP5562=y
CONFIG_LEDS_LP8501=m
CONFIG_LEDS_LP8860=m
CONFIG_LEDS_CLEVO_MAIL=m
CONFIG_LEDS_PCA955X=y
# CONFIG_LEDS_PCA963X is not set
CONFIG_LEDS_WM831X_STATUS=y
# CONFIG_LEDS_WM8350 is not set
# CONFIG_LEDS_PWM is not set
CONFIG_LEDS_BD2802=m
# CONFIG_LEDS_INTEL_SS4200 is not set
CONFIG_LEDS_LT3593=y
# CONFIG_LEDS_TCA6507 is not set
CONFIG_LEDS_TLC591XX=y
CONFIG_LEDS_LM355x=y
CONFIG_LEDS_OT200=y

#
# LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)
#
# CONFIG_LEDS_BLINKM is not set

#
# LED Triggers
#
CONFIG_LEDS_TRIGGERS=y
# CONFIG_LEDS_TRIGGER_TIMER is not set
CONFIG_LEDS_TRIGGER_ONESHOT=y
# CONFIG_LEDS_TRIGGER_MTD is not set
CONFIG_LEDS_TRIGGER_HEARTBEAT=m
CONFIG_LEDS_TRIGGER_BACKLIGHT=y
CONFIG_LEDS_TRIGGER_CPU=y
CONFIG_LEDS_TRIGGER_GPIO=y
# CONFIG_LEDS_TRIGGER_DEFAULT_ON is not set

#
# iptables trigger is under Netfilter config (LED target)
#
# CONFIG_LEDS_TRIGGER_TRANSIENT is not set
CONFIG_LEDS_TRIGGER_CAMERA=y
CONFIG_LEDS_TRIGGER_PANIC=y
CONFIG_ACCESSIBILITY=y
CONFIG_EDAC_ATOMIC_SCRUB=y
CONFIG_EDAC_SUPPORT=y
CONFIG_EDAC=y
CONFIG_EDAC_LEGACY_SYSFS=y
# CONFIG_EDAC_DEBUG is not set
CONFIG_EDAC_MM_EDAC=m
# CONFIG_EDAC_AMD76X is not set
CONFIG_EDAC_E7XXX=m
CONFIG_EDAC_E752X=m
CONFIG_EDAC_I82875P=m
# CONFIG_EDAC_I82975X is not set
CONFIG_EDAC_I3000=m
CONFIG_EDAC_I3200=m
# CONFIG_EDAC_IE31200 is not set
CONFIG_EDAC_X38=m
CONFIG_EDAC_I5400=m
CONFIG_EDAC_I82860=m
# CONFIG_EDAC_R82600 is not set
CONFIG_EDAC_I5000=m
# CONFIG_EDAC_I5100 is not set
# CONFIG_EDAC_I7300 is not set
CONFIG_RTC_LIB=y
CONFIG_RTC_MC146818_LIB=y
CONFIG_RTC_CLASS=y
CONFIG_RTC_HCTOSYS=y
CONFIG_RTC_HCTOSYS_DEVICE="rtc0"
# CONFIG_RTC_SYSTOHC is not set
CONFIG_RTC_DEBUG=y

#
# RTC interfaces
#
CONFIG_RTC_INTF_SYSFS=y
CONFIG_RTC_INTF_PROC=y
# CONFIG_RTC_INTF_DEV is not set
CONFIG_RTC_DRV_TEST=m

#
# I2C RTC drivers
#
# CONFIG_RTC_DRV_88PM860X is not set
# CONFIG_RTC_DRV_88PM80X is not set
CONFIG_RTC_DRV_ABB5ZES3=m
CONFIG_RTC_DRV_ABX80X=m
CONFIG_RTC_DRV_DS1307=m
# CONFIG_RTC_DRV_DS1307_HWMON is not set
# CONFIG_RTC_DRV_DS1374 is not set
CONFIG_RTC_DRV_DS1672=m
# CONFIG_RTC_DRV_MAX6900 is not set
# CONFIG_RTC_DRV_MAX8925 is not set
CONFIG_RTC_DRV_MAX8998=m
CONFIG_RTC_DRV_RS5C372=m
# CONFIG_RTC_DRV_ISL1208 is not set
CONFIG_RTC_DRV_ISL12022=m
CONFIG_RTC_DRV_ISL12057=m
# CONFIG_RTC_DRV_X1205 is not set
CONFIG_RTC_DRV_PCF8523=m
CONFIG_RTC_DRV_PCF85063=y
CONFIG_RTC_DRV_PCF8563=m
# CONFIG_RTC_DRV_PCF8583 is not set
CONFIG_RTC_DRV_M41T80=y
# CONFIG_RTC_DRV_M41T80_WDT is not set
# CONFIG_RTC_DRV_BQ32K is not set
CONFIG_RTC_DRV_TWL4030=m
# CONFIG_RTC_DRV_PALMAS is not set
# CONFIG_RTC_DRV_S35390A is not set
CONFIG_RTC_DRV_FM3130=m
CONFIG_RTC_DRV_RX8010=y
CONFIG_RTC_DRV_RX8581=m
# CONFIG_RTC_DRV_RX8025 is not set
CONFIG_RTC_DRV_EM3027=y
# CONFIG_RTC_DRV_RV8803 is not set

#
# SPI RTC drivers
#
CONFIG_RTC_I2C_AND_SPI=y

#
# SPI and I2C RTC drivers
#
# CONFIG_RTC_DRV_DS3232 is not set
CONFIG_RTC_DRV_PCF2127=y
# CONFIG_RTC_DRV_RV3029C2 is not set

#
# Platform RTC drivers
#
CONFIG_RTC_DRV_CMOS=y
CONFIG_RTC_DRV_DS1286=y
# CONFIG_RTC_DRV_DS1511 is not set
CONFIG_RTC_DRV_DS1553=y
CONFIG_RTC_DRV_DS1685_FAMILY=m
# CONFIG_RTC_DRV_DS1685 is not set
# CONFIG_RTC_DRV_DS1689 is not set
# CONFIG_RTC_DRV_DS17285 is not set
# CONFIG_RTC_DRV_DS17485 is not set
CONFIG_RTC_DRV_DS17885=y
# CONFIG_RTC_DS1685_PROC_REGS is not set
CONFIG_RTC_DS1685_SYSFS_REGS=y
CONFIG_RTC_DRV_DS1742=y
CONFIG_RTC_DRV_DS2404=y
CONFIG_RTC_DRV_DA9063=y
# CONFIG_RTC_DRV_STK17TA8 is not set
# CONFIG_RTC_DRV_M48T86 is not set
# CONFIG_RTC_DRV_M48T35 is not set
# CONFIG_RTC_DRV_M48T59 is not set
CONFIG_RTC_DRV_MSM6242=m
CONFIG_RTC_DRV_BQ4802=y
CONFIG_RTC_DRV_RP5C01=y
# CONFIG_RTC_DRV_V3020 is not set
# CONFIG_RTC_DRV_WM831X is not set
# CONFIG_RTC_DRV_WM8350 is not set

#
# on-CPU RTC drivers
#
# CONFIG_RTC_DRV_MT6397 is not set

#
# HID Sensor RTC drivers
#
CONFIG_DMADEVICES=y
# CONFIG_DMADEVICES_DEBUG is not set

#
# DMA Devices
#
CONFIG_DMA_ENGINE=y
CONFIG_DMA_VIRTUAL_CHANNELS=y
CONFIG_DMA_ACPI=y
CONFIG_INTEL_IDMA64=y
CONFIG_PCH_DMA=y
CONFIG_TIMB_DMA=m
CONFIG_QCOM_HIDMA_MGMT=m
CONFIG_QCOM_HIDMA=y
CONFIG_DW_DMAC_CORE=y
CONFIG_DW_DMAC=m
CONFIG_DW_DMAC_PCI=y
CONFIG_HSU_DMA=y

#
# DMA Clients
#
# CONFIG_ASYNC_TX_DMA is not set
# CONFIG_DMATEST is not set

#
# DMABUF options
#
# CONFIG_SYNC_FILE is not set
CONFIG_AUXDISPLAY=y
CONFIG_UIO=m
CONFIG_UIO_CIF=m
CONFIG_UIO_PDRV_GENIRQ=m
CONFIG_UIO_DMEM_GENIRQ=m
CONFIG_UIO_AEC=m
CONFIG_UIO_SERCOS3=m
CONFIG_UIO_PCI_GENERIC=m
CONFIG_UIO_NETX=m
CONFIG_UIO_PRUSS=m
CONFIG_UIO_MF624=m
# CONFIG_VIRT_DRIVERS is not set
CONFIG_VIRTIO=y

#
# Virtio drivers
#
CONFIG_VIRTIO_PCI=y
CONFIG_VIRTIO_PCI_LEGACY=y
CONFIG_VIRTIO_BALLOON=m
CONFIG_VIRTIO_INPUT=m
CONFIG_VIRTIO_MMIO=m
# CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES is not set

#
# Microsoft Hyper-V guest support
#
# CONFIG_HYPERV is not set
CONFIG_STAGING=y
# CONFIG_SLICOSS is not set
# CONFIG_COMEDI is not set

#
# IIO staging drivers
#

#
# Accelerometers
#

#
# Analog to digital converters
#
# CONFIG_AD7606 is not set

#
# Analog digital bi-direction converters
#
# CONFIG_ADT7316 is not set

#
# Capacitance to digital converters
#
# CONFIG_AD7150 is not set
CONFIG_AD7152=m
# CONFIG_AD7746 is not set

#
# Direct Digital Synthesis
#

#
# Digital gyroscope sensors
#

#
# Network Analyzer, Impedance Converters
#
CONFIG_AD5933=m

#
# Light sensors
#
CONFIG_SENSORS_ISL29018=m
# CONFIG_SENSORS_ISL29028 is not set
CONFIG_TSL2583=m
# CONFIG_TSL2x7x is not set

#
# Active energy metering IC
#
CONFIG_ADE7854=m
# CONFIG_ADE7854_I2C is not set

#
# Resolver to digital converters
#

#
# Triggers - standalone
#
CONFIG_FB_SM750=m
# CONFIG_FB_XGI is not set

#
# Speakup console speech
#
# CONFIG_STAGING_MEDIA is not set

#
# Android
#
CONFIG_ASHMEM=y
# CONFIG_ANDROID_LOW_MEMORY_KILLER is not set
# CONFIG_ION is not set
# CONFIG_FIREWIRE_SERIAL is not set
# CONFIG_DGNC is not set
CONFIG_GS_FPGABOOT=y
# CONFIG_MOST is not set
# CONFIG_KS7010 is not set
# CONFIG_X86_PLATFORM_DEVICES is not set
# CONFIG_CHROME_PLATFORMS is not set
CONFIG_CLKDEV_LOOKUP=y
CONFIG_HAVE_CLK_PREPARE=y
CONFIG_COMMON_CLK=y

#
# Common Clock Framework
#
CONFIG_COMMON_CLK_WM831X=m
CONFIG_COMMON_CLK_SI5351=m
CONFIG_COMMON_CLK_CDCE706=y
# CONFIG_COMMON_CLK_CS2000_CP is not set
# CONFIG_CLK_TWL6040 is not set
# CONFIG_COMMON_CLK_NXP is not set
CONFIG_COMMON_CLK_PALMAS=y
CONFIG_COMMON_CLK_PWM=m
# CONFIG_COMMON_CLK_PXA is not set
# CONFIG_COMMON_CLK_PIC32 is not set
# CONFIG_SUNXI_CCU is not set

#
# Hardware Spinlock drivers
#

#
# Clock Source drivers
#
CONFIG_CLKSRC_I8253=y
CONFIG_CLKEVT_I8253=y
CONFIG_CLKBLD_I8253=y
# CONFIG_ATMEL_PIT is not set
# CONFIG_SH_TIMER_CMT is not set
# CONFIG_SH_TIMER_MTU2 is not set
# CONFIG_SH_TIMER_TMU is not set
# CONFIG_EM_TIMER_STI is not set
# CONFIG_MAILBOX is not set
# CONFIG_IOMMU_SUPPORT is not set

#
# Remoteproc drivers
#
CONFIG_REMOTEPROC=y
CONFIG_STE_MODEM_RPROC=y

#
# Rpmsg drivers
#

#
# SOC (System On Chip) specific Drivers
#

#
# Broadcom SoC drivers
#
# CONFIG_SUNXI_SRAM is not set
CONFIG_SOC_TI=y
# CONFIG_PM_DEVFREQ is not set
CONFIG_EXTCON=y

#
# Extcon Device Drivers
#
CONFIG_EXTCON_ADC_JACK=m
# CONFIG_EXTCON_GPIO is not set
CONFIG_EXTCON_MAX14577=m
# CONFIG_EXTCON_MAX3355 is not set
CONFIG_EXTCON_MAX77693=m
# CONFIG_EXTCON_PALMAS is not set
# CONFIG_EXTCON_RT8973A is not set
CONFIG_EXTCON_SM5502=y
# CONFIG_EXTCON_USB_GPIO is not set
CONFIG_MEMORY=y
CONFIG_IIO=m
CONFIG_IIO_BUFFER=y
# CONFIG_IIO_BUFFER_CB is not set
CONFIG_IIO_KFIFO_BUF=m
CONFIG_IIO_TRIGGERED_BUFFER=m
CONFIG_IIO_CONFIGFS=m
CONFIG_IIO_TRIGGER=y
CONFIG_IIO_CONSUMERS_PER_TRIGGER=2
# CONFIG_IIO_SW_DEVICE is not set
# CONFIG_IIO_SW_TRIGGER is not set

#
# Accelerometers
#
# CONFIG_BMA180 is not set
CONFIG_BMC150_ACCEL=m
CONFIG_BMC150_ACCEL_I2C=m
CONFIG_IIO_ST_ACCEL_3AXIS=m
CONFIG_IIO_ST_ACCEL_I2C_3AXIS=m
CONFIG_KXCJK1013=m
# CONFIG_MMA7455_I2C is not set
CONFIG_MMA7660=m
CONFIG_MMA8452=m
CONFIG_MMA9551_CORE=m
# CONFIG_MMA9551 is not set
CONFIG_MMA9553=m
CONFIG_MXC4005=m
CONFIG_MXC6255=m
CONFIG_STK8312=m
CONFIG_STK8BA50=m

#
# Analog to digital converters
#
# CONFIG_AD7291 is not set
CONFIG_AD799X=m
CONFIG_MAX1363=m
CONFIG_MCP3422=m
CONFIG_NAU7802=m
CONFIG_PALMAS_GPADC=m
CONFIG_QCOM_SPMI_IADC=m
CONFIG_QCOM_SPMI_VADC=m
CONFIG_TI_ADC081C=m
# CONFIG_TI_AM335X_ADC is not set
CONFIG_TWL4030_MADC=m
# CONFIG_TWL6030_GPADC is not set

#
# Amplifiers
#

#
# Chemical Sensors
#
# CONFIG_ATLAS_PH_SENSOR is not set
CONFIG_IAQCORE=m
CONFIG_VZ89X=m

#
# Hid Sensor IIO Common
#
CONFIG_IIO_MS_SENSORS_I2C=m

#
# SSP Sensor Common
#
CONFIG_IIO_ST_SENSORS_I2C=m
CONFIG_IIO_ST_SENSORS_CORE=m

#
# Digital to analog converters
#
CONFIG_AD5064=m
CONFIG_AD5380=m
CONFIG_AD5446=m
# CONFIG_AD5593R is not set
# CONFIG_M62332 is not set
CONFIG_MAX517=m
CONFIG_MCP4725=m
# CONFIG_STX104 is not set

#
# IIO dummy driver
#

#
# Frequency Synthesizers DDS/PLL
#

#
# Clock Generator/Distribution
#

#
# Phase-Locked Loop (PLL) frequency synthesizers
#

#
# Digital gyroscope sensors
#
# CONFIG_BMG160 is not set
# CONFIG_IIO_ST_GYRO_3AXIS is not set
CONFIG_ITG3200=m

#
# Health Sensors
#

#
# Heart Rate Monitors
#
CONFIG_AFE4404=m
CONFIG_MAX30100=m

#
# Humidity sensors
#
# CONFIG_AM2315 is not set
# CONFIG_DHT11 is not set
CONFIG_HDC100X=m
CONFIG_HTU21=m
CONFIG_SI7005=m
CONFIG_SI7020=m

#
# Inertial measurement units
#
CONFIG_BMI160=m
CONFIG_BMI160_I2C=m
CONFIG_KMX61=m

#
# Light sensors
#
CONFIG_ACPI_ALS=m
CONFIG_ADJD_S311=m
CONFIG_AL3320A=m
# CONFIG_APDS9300 is not set
# CONFIG_APDS9960 is not set
# CONFIG_BH1750 is not set
CONFIG_BH1780=m
# CONFIG_CM32181 is not set
CONFIG_CM3232=m
# CONFIG_CM3323 is not set
# CONFIG_CM36651 is not set
CONFIG_GP2AP020A00F=m
# CONFIG_ISL29125 is not set
CONFIG_JSA1212=m
CONFIG_RPR0521=m
CONFIG_SENSORS_LM3533=m
# CONFIG_LTR501 is not set
CONFIG_MAX44000=m
# CONFIG_OPT3001 is not set
CONFIG_PA12203001=m
CONFIG_STK3310=m
# CONFIG_TCS3414 is not set
CONFIG_TCS3472=m
# CONFIG_SENSORS_TSL2563 is not set
CONFIG_TSL4531=m
CONFIG_US5182D=m
CONFIG_VCNL4000=m
CONFIG_VEML6070=m

#
# Magnetometer sensors
#
CONFIG_AK8975=m
CONFIG_AK09911=m
CONFIG_BMC150_MAGN=m
CONFIG_BMC150_MAGN_I2C=m
# CONFIG_MAG3110 is not set
CONFIG_MMC35240=m
CONFIG_IIO_ST_MAGN_3AXIS=m
CONFIG_IIO_ST_MAGN_I2C_3AXIS=m
CONFIG_SENSORS_HMC5843=m
CONFIG_SENSORS_HMC5843_I2C=m

#
# Inclinometer sensors
#

#
# Triggers - standalone
#
CONFIG_IIO_INTERRUPT_TRIGGER=m
# CONFIG_IIO_SYSFS_TRIGGER is not set

#
# Digital potentiometers
#
# CONFIG_DS1803 is not set
CONFIG_MCP4531=m
# CONFIG_TPL0102 is not set

#
# Pressure sensors
#
CONFIG_HP03=m
CONFIG_MPL115=m
CONFIG_MPL115_I2C=m
CONFIG_MPL3115=m
CONFIG_MS5611=m
CONFIG_MS5611_I2C=m
CONFIG_MS5637=m
CONFIG_IIO_ST_PRESS=m
CONFIG_IIO_ST_PRESS_I2C=m
CONFIG_T5403=m
# CONFIG_HP206C is not set

#
# Lightning sensors
#

#
# Proximity sensors
#
# CONFIG_LIDAR_LITE_V2 is not set
# CONFIG_SX9500 is not set

#
# Temperature sensors
#
# CONFIG_MLX90614 is not set
CONFIG_TMP006=m
CONFIG_TSYS01=m
CONFIG_TSYS02D=m
# CONFIG_NTB is not set
CONFIG_VME_BUS=y

#
# VME Bridge Drivers
#
# CONFIG_VME_CA91CX42 is not set
CONFIG_VME_TSI148=m

#
# VME Board Drivers
#
# CONFIG_VMIVME_7805 is not set

#
# VME Device Drivers
#
CONFIG_VME_USER=m
CONFIG_VME_PIO2=m
CONFIG_PWM=y
CONFIG_PWM_SYSFS=y
CONFIG_PWM_LP3943=m
CONFIG_PWM_LPSS=m
CONFIG_PWM_LPSS_PCI=m
# CONFIG_PWM_LPSS_PLATFORM is not set
# CONFIG_PWM_PCA9685 is not set
CONFIG_PWM_TWL=y
CONFIG_PWM_TWL_LED=y
CONFIG_ARM_GIC_MAX_NR=1
# CONFIG_IPACK_BUS is not set
CONFIG_RESET_CONTROLLER=y
CONFIG_TI_SYSCON_RESET=m
CONFIG_FMC=y
CONFIG_FMC_FAKEDEV=m
CONFIG_FMC_TRIVIAL=y
CONFIG_FMC_WRITE_EEPROM=y
CONFIG_FMC_CHARDEV=m

#
# PHY Subsystem
#
CONFIG_GENERIC_PHY=y
# CONFIG_PHY_PXA_28NM_HSIC is not set
CONFIG_PHY_PXA_28NM_USB2=m
# CONFIG_BCM_KONA_USB2_PHY is not set
CONFIG_POWERCAP=y
CONFIG_INTEL_RAPL=m
# CONFIG_MCB is not set

#
# Performance monitor support
#
CONFIG_RAS=y
# CONFIG_THUNDERBOLT is not set

#
# Android
#
CONFIG_ANDROID=y
# CONFIG_ANDROID_BINDER_IPC is not set
CONFIG_NVMEM=m
# CONFIG_STM is not set
CONFIG_INTEL_TH=m
CONFIG_INTEL_TH_PCI=m
CONFIG_INTEL_TH_GTH=m
CONFIG_INTEL_TH_MSU=m
CONFIG_INTEL_TH_PTI=m
CONFIG_INTEL_TH_DEBUG=y

#
# FPGA Configuration Support
#
CONFIG_FPGA=y
CONFIG_FPGA_MGR_ZYNQ_FPGA=m

#
# Firmware Drivers
#
CONFIG_EDD=m
# CONFIG_EDD_OFF is not set
# CONFIG_FIRMWARE_MEMMAP is not set
CONFIG_DELL_RBU=y
CONFIG_DCDBAS=y
CONFIG_DMIID=y
CONFIG_DMI_SYSFS=m
CONFIG_DMI_SCAN_MACHINE_NON_EFI_FALLBACK=y
# CONFIG_ISCSI_IBFT_FIND is not set
# CONFIG_FW_CFG_SYSFS is not set
CONFIG_GOOGLE_FIRMWARE=y

#
# Google Firmware Drivers
#
# CONFIG_GOOGLE_SMI is not set
# CONFIG_GOOGLE_MEMCONSOLE is not set

#
# EFI (Extensible Firmware Interface) Support
#
CONFIG_EFI_VARS=y
CONFIG_EFI_ESRT=y
# CONFIG_EFI_RUNTIME_MAP is not set
# CONFIG_EFI_FAKE_MEMMAP is not set
CONFIG_EFI_RUNTIME_WRAPPERS=y
# CONFIG_EFI_BOOTLOADER_CONTROL is not set
# CONFIG_EFI_CAPSULE_LOADER is not set

#
# File systems
#
CONFIG_DCACHE_WORD_ACCESS=y
# CONFIG_FS_POSIX_ACL is not set
CONFIG_EXPORTFS=y
# CONFIG_EXPORTFS_BLOCK_OPS is not set
CONFIG_FILE_LOCKING=y
CONFIG_MANDATORY_FILE_LOCKING=y
CONFIG_FSNOTIFY=y
# CONFIG_DNOTIFY is not set
CONFIG_INOTIFY_USER=y
# CONFIG_FANOTIFY is not set
CONFIG_QUOTA=y
# CONFIG_QUOTA_NETLINK_INTERFACE is not set
# CONFIG_PRINT_QUOTA_WARNING is not set
CONFIG_QUOTA_DEBUG=y
CONFIG_QUOTA_TREE=y
CONFIG_QFMT_V1=y
CONFIG_QFMT_V2=y
CONFIG_QUOTACTL=y
CONFIG_AUTOFS4_FS=y
CONFIG_FUSE_FS=m
CONFIG_CUSE=m
# CONFIG_OVERLAY_FS is not set

#
# Caches
#
CONFIG_FSCACHE=m
CONFIG_FSCACHE_STATS=y
CONFIG_FSCACHE_HISTOGRAM=y
CONFIG_FSCACHE_DEBUG=y
# CONFIG_FSCACHE_OBJECT_LIST is not set

#
# Pseudo filesystems
#
CONFIG_PROC_FS=y
CONFIG_PROC_KCORE=y
CONFIG_PROC_VMCORE=y
# CONFIG_PROC_SYSCTL is not set
CONFIG_PROC_PAGE_MONITOR=y
CONFIG_PROC_CHILDREN=y
CONFIG_KERNFS=y
CONFIG_SYSFS=y
CONFIG_TMPFS=y
# CONFIG_TMPFS_POSIX_ACL is not set
# CONFIG_TMPFS_XATTR is not set
CONFIG_HUGETLBFS=y
CONFIG_HUGETLB_PAGE=y
CONFIG_CONFIGFS_FS=y
CONFIG_EFIVAR_FS=m
# CONFIG_MISC_FILESYSTEMS is not set
CONFIG_NETWORK_FILESYSTEMS=y
CONFIG_NLS=y
CONFIG_NLS_DEFAULT="iso8859-1"
CONFIG_NLS_CODEPAGE_437=y
CONFIG_NLS_CODEPAGE_737=y
CONFIG_NLS_CODEPAGE_775=y
CONFIG_NLS_CODEPAGE_850=y
CONFIG_NLS_CODEPAGE_852=y
# CONFIG_NLS_CODEPAGE_855 is not set
CONFIG_NLS_CODEPAGE_857=y
CONFIG_NLS_CODEPAGE_860=m
CONFIG_NLS_CODEPAGE_861=m
CONFIG_NLS_CODEPAGE_862=m
# CONFIG_NLS_CODEPAGE_863 is not set
CONFIG_NLS_CODEPAGE_864=m
CONFIG_NLS_CODEPAGE_865=m
# CONFIG_NLS_CODEPAGE_866 is not set
CONFIG_NLS_CODEPAGE_869=m
CONFIG_NLS_CODEPAGE_936=y
# CONFIG_NLS_CODEPAGE_950 is not set
CONFIG_NLS_CODEPAGE_932=y
CONFIG_NLS_CODEPAGE_949=y
CONFIG_NLS_CODEPAGE_874=y
CONFIG_NLS_ISO8859_8=y
# CONFIG_NLS_CODEPAGE_1250 is not set
CONFIG_NLS_CODEPAGE_1251=y
CONFIG_NLS_ASCII=y
# CONFIG_NLS_ISO8859_1 is not set
CONFIG_NLS_ISO8859_2=y
CONFIG_NLS_ISO8859_3=m
CONFIG_NLS_ISO8859_4=m
CONFIG_NLS_ISO8859_5=y
CONFIG_NLS_ISO8859_6=y
CONFIG_NLS_ISO8859_7=m
# CONFIG_NLS_ISO8859_9 is not set
CONFIG_NLS_ISO8859_13=y
CONFIG_NLS_ISO8859_14=m
CONFIG_NLS_ISO8859_15=y
# CONFIG_NLS_KOI8_R is not set
CONFIG_NLS_KOI8_U=m
# CONFIG_NLS_MAC_ROMAN is not set
CONFIG_NLS_MAC_CELTIC=m
CONFIG_NLS_MAC_CENTEURO=m
CONFIG_NLS_MAC_CROATIAN=m
# CONFIG_NLS_MAC_CYRILLIC is not set
# CONFIG_NLS_MAC_GAELIC is not set
# CONFIG_NLS_MAC_GREEK is not set
CONFIG_NLS_MAC_ICELAND=m
# CONFIG_NLS_MAC_INUIT is not set
# CONFIG_NLS_MAC_ROMANIAN is not set
# CONFIG_NLS_MAC_TURKISH is not set
# CONFIG_NLS_UTF8 is not set

#
# Kernel hacking
#
CONFIG_TRACE_IRQFLAGS_SUPPORT=y

#
# printk and dmesg options
#
CONFIG_PRINTK_TIME=y
CONFIG_MESSAGE_LOGLEVEL_DEFAULT=4
# CONFIG_BOOT_PRINTK_DELAY is not set
# CONFIG_DYNAMIC_DEBUG is not set

#
# Compile-time checks and compiler options
#
# CONFIG_DEBUG_INFO is not set
CONFIG_ENABLE_WARN_DEPRECATED=y
CONFIG_ENABLE_MUST_CHECK=y
CONFIG_FRAME_WARN=1024
CONFIG_STRIP_ASM_SYMS=y
# CONFIG_READABLE_ASM is not set
# CONFIG_UNUSED_SYMBOLS is not set
CONFIG_PAGE_OWNER=y
CONFIG_DEBUG_FS=y
CONFIG_HEADERS_CHECK=y
CONFIG_DEBUG_SECTION_MISMATCH=y
CONFIG_SECTION_MISMATCH_WARN_ONLY=y
CONFIG_ARCH_WANT_FRAME_POINTERS=y
CONFIG_FRAME_POINTER=y
# CONFIG_DEBUG_FORCE_WEAK_PER_CPU is not set
CONFIG_MAGIC_SYSRQ=y
CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE=0x1
CONFIG_DEBUG_KERNEL=y

#
# Memory Debugging
#
CONFIG_PAGE_EXTENSION=y
# CONFIG_DEBUG_PAGEALLOC is not set
# CONFIG_PAGE_POISONING is not set
# CONFIG_DEBUG_PAGE_REF is not set
CONFIG_DEBUG_OBJECTS=y
CONFIG_DEBUG_OBJECTS_SELFTEST=y
CONFIG_DEBUG_OBJECTS_FREE=y
CONFIG_DEBUG_OBJECTS_TIMERS=y
# CONFIG_DEBUG_OBJECTS_WORK is not set
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
CONFIG_DEBUG_OBJECTS_PERCPU_COUNTER=y
CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT=1
CONFIG_DEBUG_SLAB=y
CONFIG_DEBUG_SLAB_LEAK=y
CONFIG_HAVE_DEBUG_KMEMLEAK=y
# CONFIG_DEBUG_KMEMLEAK is not set
# CONFIG_DEBUG_STACK_USAGE is not set
CONFIG_DEBUG_VM=y
# CONFIG_DEBUG_VM_VMACACHE is not set
# CONFIG_DEBUG_VM_RB is not set
CONFIG_DEBUG_VM_PGFLAGS=y
CONFIG_DEBUG_VIRTUAL=y
# CONFIG_DEBUG_MEMORY_INIT is not set
CONFIG_MEMORY_NOTIFIER_ERROR_INJECT=y
# CONFIG_DEBUG_PER_CPU_MAPS is not set
# CONFIG_DEBUG_HIGHMEM is not set
CONFIG_HAVE_DEBUG_STACKOVERFLOW=y
CONFIG_DEBUG_STACKOVERFLOW=y
CONFIG_HAVE_ARCH_KMEMCHECK=y
CONFIG_DEBUG_SHIRQ=y

#
# Debug Lockups and Hangs
#
# CONFIG_LOCKUP_DETECTOR is not set
# CONFIG_DETECT_HUNG_TASK is not set
# CONFIG_WQ_WATCHDOG is not set
# CONFIG_PANIC_ON_OOPS is not set
CONFIG_PANIC_ON_OOPS_VALUE=0
CONFIG_PANIC_TIMEOUT=0
CONFIG_SCHED_DEBUG=y
CONFIG_SCHED_INFO=y
CONFIG_SCHEDSTATS=y
# CONFIG_SCHED_STACK_END_CHECK is not set
# CONFIG_DEBUG_TIMEKEEPING is not set
# CONFIG_TIMER_STATS is not set
CONFIG_DEBUG_PREEMPT=y

#
# Lock Debugging (spinlocks, mutexes, etc...)
#
CONFIG_DEBUG_RT_MUTEXES=y
CONFIG_DEBUG_SPINLOCK=y
CONFIG_DEBUG_MUTEXES=y
# CONFIG_DEBUG_WW_MUTEX_SLOWPATH is not set
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_PROVE_LOCKING=y
CONFIG_LOCKDEP=y
# CONFIG_LOCK_STAT is not set
CONFIG_DEBUG_LOCKDEP=y
CONFIG_DEBUG_ATOMIC_SLEEP=y
CONFIG_DEBUG_LOCKING_API_SELFTESTS=y
CONFIG_LOCK_TORTURE_TEST=y
CONFIG_TRACE_IRQFLAGS=y
CONFIG_STACKTRACE=y
# CONFIG_DEBUG_KOBJECT is not set
# CONFIG_DEBUG_KOBJECT_RELEASE is not set
CONFIG_DEBUG_BUGVERBOSE=y
CONFIG_DEBUG_LIST=y
CONFIG_DEBUG_PI_LIST=y
CONFIG_DEBUG_SG=y
# CONFIG_DEBUG_NOTIFIERS is not set
# CONFIG_DEBUG_CREDENTIALS is not set

#
# RCU Debugging
#
CONFIG_PROVE_RCU=y
# CONFIG_PROVE_RCU_REPEATEDLY is not set
CONFIG_SPARSE_RCU_POINTER=y
CONFIG_TORTURE_TEST=y
# CONFIG_RCU_PERF_TEST is not set
CONFIG_RCU_TORTURE_TEST=m
CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT=y
CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT_DELAY=3
CONFIG_RCU_TORTURE_TEST_SLOW_INIT=y
CONFIG_RCU_TORTURE_TEST_SLOW_INIT_DELAY=3
CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP=y
CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY=3
CONFIG_RCU_CPU_STALL_TIMEOUT=21
CONFIG_RCU_TRACE=y
CONFIG_RCU_EQS_DEBUG=y
CONFIG_DEBUG_WQ_FORCE_RR_CPU=y
CONFIG_NOTIFIER_ERROR_INJECTION=y
# CONFIG_NETDEV_NOTIFIER_ERROR_INJECT is not set
CONFIG_FAULT_INJECTION=y
# CONFIG_FAILSLAB is not set
# CONFIG_FAIL_PAGE_ALLOC is not set
CONFIG_FAIL_FUTEX=y
# CONFIG_FAULT_INJECTION_DEBUG_FS is not set
CONFIG_LATENCYTOP=y
CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS=y
CONFIG_USER_STACKTRACE_SUPPORT=y
CONFIG_NOP_TRACER=y
CONFIG_HAVE_FUNCTION_TRACER=y
CONFIG_HAVE_FUNCTION_GRAPH_TRACER=y
CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST=y
CONFIG_HAVE_DYNAMIC_FTRACE=y
CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS=y
CONFIG_HAVE_FTRACE_MCOUNT_RECORD=y
CONFIG_HAVE_SYSCALL_TRACEPOINTS=y
CONFIG_HAVE_C_RECORDMCOUNT=y
CONFIG_TRACER_MAX_TRACE=y
CONFIG_TRACE_CLOCK=y
CONFIG_RING_BUFFER=y
CONFIG_EVENT_TRACING=y
CONFIG_CONTEXT_SWITCH_TRACER=y
CONFIG_RING_BUFFER_ALLOW_SWAP=y
CONFIG_TRACING=y
CONFIG_GENERIC_TRACER=y
CONFIG_TRACING_SUPPORT=y
CONFIG_FTRACE=y
CONFIG_FUNCTION_TRACER=y
# CONFIG_FUNCTION_GRAPH_TRACER is not set
CONFIG_IRQSOFF_TRACER=y
CONFIG_PREEMPT_TRACER=y
# CONFIG_SCHED_TRACER is not set
# CONFIG_FTRACE_SYSCALLS is not set
CONFIG_TRACER_SNAPSHOT=y
CONFIG_TRACER_SNAPSHOT_PER_CPU_SWAP=y
CONFIG_TRACE_BRANCH_PROFILING=y
# CONFIG_BRANCH_PROFILE_NONE is not set
CONFIG_PROFILE_ANNOTATED_BRANCHES=y
# CONFIG_PROFILE_ALL_BRANCHES is not set
CONFIG_TRACING_BRANCHES=y
CONFIG_BRANCH_TRACER=y
# CONFIG_STACK_TRACER is not set
CONFIG_UPROBE_EVENT=y
CONFIG_BPF_EVENTS=y
CONFIG_PROBE_EVENTS=y
# CONFIG_DYNAMIC_FTRACE is not set
CONFIG_FUNCTION_PROFILER=y
# CONFIG_FTRACE_STARTUP_TEST is not set
CONFIG_MMIOTRACE=y
CONFIG_TRACING_MAP=y
CONFIG_HIST_TRIGGERS=y
# CONFIG_MMIOTRACE_TEST is not set
# CONFIG_TRACEPOINT_BENCHMARK is not set
# CONFIG_RING_BUFFER_BENCHMARK is not set
# CONFIG_RING_BUFFER_STARTUP_TEST is not set
# CONFIG_TRACE_ENUM_MAP_FILE is not set
# CONFIG_TRACING_EVENTS_GPIO is not set

#
# Runtime Testing
#
CONFIG_TEST_LIST_SORT=y
# CONFIG_BACKTRACE_SELF_TEST is not set
# CONFIG_RBTREE_TEST is not set
CONFIG_INTERVAL_TREE_TEST=m
# CONFIG_PERCPU_TEST is not set
# CONFIG_ATOMIC64_SELFTEST is not set
CONFIG_TEST_HEXDUMP=m
CONFIG_TEST_STRING_HELPERS=m
CONFIG_TEST_KSTRTOX=m
CONFIG_TEST_PRINTF=y
CONFIG_TEST_BITMAP=m
CONFIG_TEST_UUID=y
CONFIG_TEST_RHASHTABLE=y
# CONFIG_TEST_HASH is not set
# CONFIG_PROVIDE_OHCI1394_DMA_INIT is not set
CONFIG_BUILD_DOCSRC=y
# CONFIG_DMA_API_DEBUG is not set
CONFIG_TEST_LKM=m
CONFIG_TEST_USER_COPY=m
# CONFIG_TEST_BPF is not set
CONFIG_TEST_FIRMWARE=m
CONFIG_TEST_UDELAY=y
CONFIG_MEMTEST=y
CONFIG_TEST_STATIC_KEYS=m
# CONFIG_SAMPLES is not set
CONFIG_HAVE_ARCH_KGDB=y
# CONFIG_KGDB is not set
CONFIG_ARCH_HAS_UBSAN_SANITIZE_ALL=y
CONFIG_UBSAN=y
# CONFIG_UBSAN_SANITIZE_ALL is not set
# CONFIG_UBSAN_ALIGNMENT is not set
CONFIG_ARCH_HAS_DEVMEM_IS_ALLOWED=y
CONFIG_STRICT_DEVMEM=y
# CONFIG_IO_STRICT_DEVMEM is not set
CONFIG_X86_VERBOSE_BOOTUP=y
# CONFIG_EARLY_PRINTK is not set
CONFIG_X86_PTDUMP_CORE=y
# CONFIG_X86_PTDUMP is not set
# CONFIG_EFI_PGT_DUMP is not set
CONFIG_DEBUG_RODATA_TEST=y
CONFIG_DEBUG_WX=y
CONFIG_DEBUG_SET_MODULE_RONX=y
# CONFIG_DEBUG_NX_TEST is not set
CONFIG_DOUBLEFAULT=y
# CONFIG_DEBUG_TLBFLUSH is not set
# CONFIG_IOMMU_STRESS is not set
CONFIG_HAVE_MMIOTRACE_SUPPORT=y
CONFIG_IO_DELAY_TYPE_0X80=0
CONFIG_IO_DELAY_TYPE_0XED=1
CONFIG_IO_DELAY_TYPE_UDELAY=2
CONFIG_IO_DELAY_TYPE_NONE=3
# CONFIG_IO_DELAY_0X80 is not set
# CONFIG_IO_DELAY_0XED is not set
# CONFIG_IO_DELAY_UDELAY is not set
CONFIG_IO_DELAY_NONE=y
CONFIG_DEFAULT_IO_DELAY_TYPE=3
# CONFIG_DEBUG_BOOT_PARAMS is not set
# CONFIG_CPA_DEBUG is not set
# CONFIG_OPTIMIZE_INLINING is not set
CONFIG_DEBUG_ENTRY=y
# CONFIG_DEBUG_NMI_SELFTEST is not set
# CONFIG_X86_DEBUG_FPU is not set
CONFIG_PUNIT_ATOM_DEBUG=m

#
# Security options
#
# CONFIG_KEYS is not set
CONFIG_SECURITY_DMESG_RESTRICT=y
# CONFIG_SECURITY is not set
CONFIG_SECURITYFS=y
CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR=y
CONFIG_HAVE_ARCH_HARDENED_USERCOPY=y
# CONFIG_HARDENED_USERCOPY is not set
CONFIG_DEFAULT_SECURITY_DAC=y
CONFIG_DEFAULT_SECURITY=""
CONFIG_CRYPTO=y

#
# Crypto core or helper
#
CONFIG_CRYPTO_ALGAPI=y
CONFIG_CRYPTO_ALGAPI2=y
CONFIG_CRYPTO_AEAD=y
CONFIG_CRYPTO_AEAD2=y
CONFIG_CRYPTO_BLKCIPHER=y
CONFIG_CRYPTO_BLKCIPHER2=y
CONFIG_CRYPTO_HASH=y
CONFIG_CRYPTO_HASH2=y
CONFIG_CRYPTO_RNG=y
CONFIG_CRYPTO_RNG2=y
CONFIG_CRYPTO_RNG_DEFAULT=m
CONFIG_CRYPTO_AKCIPHER2=y
CONFIG_CRYPTO_KPP2=y
CONFIG_CRYPTO_KPP=y
# CONFIG_CRYPTO_RSA is not set
CONFIG_CRYPTO_DH=y
# CONFIG_CRYPTO_ECDH is not set
CONFIG_CRYPTO_MANAGER=y
CONFIG_CRYPTO_MANAGER2=y
# CONFIG_CRYPTO_USER is not set
CONFIG_CRYPTO_MANAGER_DISABLE_TESTS=y
CONFIG_CRYPTO_GF128MUL=y
CONFIG_CRYPTO_NULL=m
CONFIG_CRYPTO_NULL2=y
CONFIG_CRYPTO_PCRYPT=m
CONFIG_CRYPTO_WORKQUEUE=y
CONFIG_CRYPTO_CRYPTD=y
# CONFIG_CRYPTO_MCRYPTD is not set
CONFIG_CRYPTO_AUTHENC=m
CONFIG_CRYPTO_TEST=m

#
# Authenticated Encryption with Associated Data
#
# CONFIG_CRYPTO_CCM is not set
# CONFIG_CRYPTO_GCM is not set
CONFIG_CRYPTO_CHACHA20POLY1305=y
CONFIG_CRYPTO_SEQIV=m
CONFIG_CRYPTO_ECHAINIV=m

#
# Block modes
#
CONFIG_CRYPTO_CBC=y
CONFIG_CRYPTO_CTR=m
CONFIG_CRYPTO_CTS=y
# CONFIG_CRYPTO_ECB is not set
CONFIG_CRYPTO_LRW=m
CONFIG_CRYPTO_PCBC=y
CONFIG_CRYPTO_XTS=y
# CONFIG_CRYPTO_KEYWRAP is not set

#
# Hash modes
#
CONFIG_CRYPTO_CMAC=m
CONFIG_CRYPTO_HMAC=m
# CONFIG_CRYPTO_XCBC is not set
CONFIG_CRYPTO_VMAC=m

#
# Digest
#
CONFIG_CRYPTO_CRC32C=m
# CONFIG_CRYPTO_CRC32C_INTEL is not set
# CONFIG_CRYPTO_CRC32 is not set
CONFIG_CRYPTO_CRC32_PCLMUL=m
CONFIG_CRYPTO_CRCT10DIF=y
CONFIG_CRYPTO_GHASH=y
CONFIG_CRYPTO_POLY1305=y
# CONFIG_CRYPTO_MD4 is not set
CONFIG_CRYPTO_MD5=y
CONFIG_CRYPTO_MICHAEL_MIC=m
# CONFIG_CRYPTO_RMD128 is not set
CONFIG_CRYPTO_RMD160=m
# CONFIG_CRYPTO_RMD256 is not set
CONFIG_CRYPTO_RMD320=m
# CONFIG_CRYPTO_SHA1 is not set
CONFIG_CRYPTO_SHA256=m
CONFIG_CRYPTO_SHA512=y
CONFIG_CRYPTO_SHA3=m
CONFIG_CRYPTO_TGR192=m
CONFIG_CRYPTO_WP512=m

#
# Ciphers
#
CONFIG_CRYPTO_AES=m
# CONFIG_CRYPTO_AES_586 is not set
# CONFIG_CRYPTO_AES_NI_INTEL is not set
CONFIG_CRYPTO_ANUBIS=m
CONFIG_CRYPTO_ARC4=m
CONFIG_CRYPTO_BLOWFISH=m
CONFIG_CRYPTO_BLOWFISH_COMMON=m
CONFIG_CRYPTO_CAMELLIA=y
CONFIG_CRYPTO_CAST_COMMON=m
# CONFIG_CRYPTO_CAST5 is not set
CONFIG_CRYPTO_CAST6=m
CONFIG_CRYPTO_DES=m
# CONFIG_CRYPTO_FCRYPT is not set
CONFIG_CRYPTO_KHAZAD=y
CONFIG_CRYPTO_SALSA20=y
CONFIG_CRYPTO_SALSA20_586=y
CONFIG_CRYPTO_CHACHA20=y
CONFIG_CRYPTO_SEED=y
CONFIG_CRYPTO_SERPENT=y
# CONFIG_CRYPTO_SERPENT_SSE2_586 is not set
# CONFIG_CRYPTO_TEA is not set
# CONFIG_CRYPTO_TWOFISH is not set
# CONFIG_CRYPTO_TWOFISH_586 is not set

#
# Compression
#
CONFIG_CRYPTO_DEFLATE=m
CONFIG_CRYPTO_LZO=m
CONFIG_CRYPTO_842=m
CONFIG_CRYPTO_LZ4=m
# CONFIG_CRYPTO_LZ4HC is not set

#
# Random Number Generation
#
# CONFIG_CRYPTO_ANSI_CPRNG is not set
CONFIG_CRYPTO_DRBG_MENU=m
CONFIG_CRYPTO_DRBG_HMAC=y
# CONFIG_CRYPTO_DRBG_HASH is not set
CONFIG_CRYPTO_DRBG_CTR=y
CONFIG_CRYPTO_DRBG=m
CONFIG_CRYPTO_JITTERENTROPY=y
# CONFIG_CRYPTO_USER_API_HASH is not set
# CONFIG_CRYPTO_USER_API_SKCIPHER is not set
# CONFIG_CRYPTO_USER_API_RNG is not set
# CONFIG_CRYPTO_USER_API_AEAD is not set
# CONFIG_CRYPTO_HW is not set

#
# Certificates for signature checking
#
CONFIG_HAVE_KVM=y
CONFIG_VIRTUALIZATION=y
# CONFIG_VHOST_NET is not set
# CONFIG_VHOST_CROSS_ENDIAN_LEGACY is not set
# CONFIG_LGUEST is not set
CONFIG_BINARY_PRINTF=y

#
# Library routines
#
CONFIG_BITREVERSE=y
# CONFIG_HAVE_ARCH_BITREVERSE is not set
CONFIG_RATIONAL=y
CONFIG_GENERIC_STRNCPY_FROM_USER=y
CONFIG_GENERIC_STRNLEN_USER=y
CONFIG_GENERIC_NET_UTILS=y
CONFIG_GENERIC_FIND_FIRST_BIT=y
CONFIG_GENERIC_PCI_IOMAP=y
CONFIG_GENERIC_IOMAP=y
CONFIG_GENERIC_IO=y
CONFIG_ARCH_HAS_FAST_MULTIPLIER=y
CONFIG_CRC_CCITT=y
CONFIG_CRC16=m
CONFIG_CRC_T10DIF=y
CONFIG_CRC_ITU_T=y
CONFIG_CRC32=y
# CONFIG_CRC32_SELFTEST is not set
# CONFIG_CRC32_SLICEBY8 is not set
# CONFIG_CRC32_SLICEBY4 is not set
# CONFIG_CRC32_SARWATE is not set
CONFIG_CRC32_BIT=y
CONFIG_CRC7=y
CONFIG_LIBCRC32C=m
CONFIG_CRC8=y
# CONFIG_AUDIT_ARCH_COMPAT_GENERIC is not set
CONFIG_RANDOM32_SELFTEST=y
CONFIG_842_COMPRESS=m
CONFIG_842_DECOMPRESS=m
CONFIG_ZLIB_INFLATE=y
CONFIG_ZLIB_DEFLATE=m
CONFIG_LZO_COMPRESS=y
CONFIG_LZO_DECOMPRESS=y
CONFIG_LZ4_COMPRESS=m
CONFIG_LZ4_DECOMPRESS=y
CONFIG_XZ_DEC=y
CONFIG_XZ_DEC_X86=y
CONFIG_XZ_DEC_POWERPC=y
# CONFIG_XZ_DEC_IA64 is not set
CONFIG_XZ_DEC_ARM=y
CONFIG_XZ_DEC_ARMTHUMB=y
# CONFIG_XZ_DEC_SPARC is not set
CONFIG_XZ_DEC_BCJ=y
CONFIG_XZ_DEC_TEST=y
CONFIG_DECOMPRESS_GZIP=y
CONFIG_DECOMPRESS_LZMA=y
CONFIG_DECOMPRESS_XZ=y
CONFIG_DECOMPRESS_LZO=y
CONFIG_DECOMPRESS_LZ4=y
CONFIG_GENERIC_ALLOCATOR=y
CONFIG_BCH=m
CONFIG_BCH_CONST_PARAMS=y
CONFIG_INTERVAL_TREE=y
CONFIG_HAS_IOMEM=y
CONFIG_HAS_IOPORT_MAP=y
CONFIG_HAS_DMA=y
CONFIG_CHECK_SIGNATURE=y
CONFIG_CPU_RMAP=y
CONFIG_DQL=y
CONFIG_NLATTR=y
CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE=y
CONFIG_CLZ_TAB=y
# CONFIG_CORDIC is not set
# CONFIG_DDR is not set
# CONFIG_IRQ_POLL is not set
CONFIG_MPILIB=y
CONFIG_UCS2_STRING=y
# CONFIG_SG_SPLIT is not set
# CONFIG_SG_POOL is not set
CONFIG_ARCH_HAS_SG_CHAIN=y
CONFIG_ARCH_HAS_MMIO_FLUSH=y
CONFIG_STACKDEPOT=y

[-- Attachment #3: dmesg.xz --]
[-- Type: application/octet-stream, Size: 13400 bytes --]

Re: [RFC PATCH-tip v4 10/10] locking/rwsem: Add a boot parameter to reader spinning threshold

[Davidlohr Bueso]

On Thu, 18 Aug 2016, Waiman Long wrote:

>The default reader spining threshold is current set to 4096. However,
>the right reader spinning threshold may vary from one system to
>another and among the different architectures. This patch adds a new
>kernel boot parameter to modify the threshold value. This enables
>better tailoring to the needs of different systems as well as for
>testing purposes.

It also means that those systems could very easily be incorrectly tailored.
(and worse case scenario: reboot, is obviously a terrible way to get rid
of any issues). I very much disagree with exposing this sort of core stuff,
it should work well for everyone out of the box, not relying on users to
properly configure this.

Thanks,
Davidlohr

Re: [RFC PATCH-tip v4 10/10] locking/rwsem: Add a boot parameter to reader spinning threshold

[Waiman Long]

On 08/24/2016 12:00 AM, Davidlohr Bueso wrote:
> On Thu, 18 Aug 2016, Waiman Long wrote:
>
>> The default reader spining threshold is current set to 4096. However,
>> the right reader spinning threshold may vary from one system to
>> another and among the different architectures. This patch adds a new
>> kernel boot parameter to modify the threshold value. This enables
>> better tailoring to the needs of different systems as well as for
>> testing purposes.
>
> It also means that those systems could very easily be incorrectly 
> tailored.
> (and worse case scenario: reboot, is obviously a terrible way to get rid
> of any issues). I very much disagree with exposing this sort of core 
> stuff,
> it should work well for everyone out of the box, not relying on users to
> properly configure this.
>
> Thanks,
> Davidlohr

I also have some concern about exposing this kernel parameter as it will 
be hard to tune. That is why I put it at the end to gauge the opinion of 
others. I will leave this out when I send out the next version.

Cheers,
Longman