[PATCH RT 0/4] Linux 3.12.22-rt35-rc1

[PATCH RT 0/4] Linux 3.12.22-rt35-rc1

[Steven Rostedt]

Dear RT Folks,

This is the RT stable review cycle of patch 3.12.22-rt35-rc1.

Please scream at me if I messed something up. Please test the patches too.

The -rc release will be uploaded to kernel.org and will be deleted when
the final release is out. This is just a review release (or release candidate).

The pre-releases will not be pushed to the git repository, only the
final release is.

If all goes well, this patch will be converted to the next main release
on 7/7/2014.

Enjoy,

-- Steve


To build 3.12.22-rt35-rc1 directly, the following patches should be applied:

  http://www.kernel.org/pub/linux/kernel/v3.x/linux-3.12.tar.xz

  http://www.kernel.org/pub/linux/kernel/v3.x/patch-3.12.22.xz

  http://www.kernel.org/pub/linux/kernel/projects/rt/3.12/patch-3.12.22-rt35-rc1.patch.xz

You can also build from 3.12.22-rt34 by applying the incremental patch:

http://www.kernel.org/pub/linux/kernel/projects/rt/3.12/incr/patch-3.12.22-rt34-rt35-rc1.patch.xz


Changes from 3.12.22-rt34:

---


Ben Hutchings (1):
      Fix latency histogram after "hrtimer: Set expiry time before switch_hrtimer_base()"

Sebastian Andrzej Siewior (2):
      Revert "migrate_disable pushd down in atomic_dec_and_spin_lock"
      timer: do not spin_trylock() on UP

Steven Rostedt (Red Hat) (1):
      Linux 3.12.22-rt35-rc1

----
 kernel/hrtimer.c | 10 +++++-----
 kernel/rtmutex.c |  6 +++---
 kernel/timer.c   | 13 +++++++++++++
 localversion-rt  |  2 +-
 4 files changed, 22 insertions(+), 9 deletions(-)

[PATCH RT 1/4] Revert "migrate_disable pushd down in atomic_dec_and_spin_lock"

[Steven Rostedt]

[-- Attachment #1: 0001-Revert-migrate_disable-pushd-down-in-atomic_dec_and_.patch --]
[-- Type: text/plain, Size: 1072 bytes --]

3.12.22-rt35-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

This reverts commit ff9c870c3e27d58c9512fad122e91436681fee5a.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/rtmutex.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 4057bc607923..d1b2ca08b160 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -952,12 +952,12 @@ int atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock)
 	/* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
 	if (atomic_add_unless(atomic, -1, 1))
 		return 0;
+	migrate_disable();
 	rt_spin_lock(lock);
-	if (atomic_dec_and_test(atomic)){
-		migrate_disable();
+	if (atomic_dec_and_test(atomic))
 		return 1;
-	}
 	rt_spin_unlock(lock);
+	migrate_enable();
 	return 0;
 }
 EXPORT_SYMBOL(atomic_dec_and_spin_lock);
-- 
2.0.0

[PATCH RT 2/4] timer: do not spin_trylock() on UP

[Steven Rostedt]

[-- Attachment #1: 0002-timer-do-not-spin_trylock-on-UP.patch --]
[-- Type: text/plain, Size: 1295 bytes --]

3.12.22-rt35-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

This will void a warning comming from the spin-lock debugging code. The
lock avoiding idea is from Steven Rostedt.

Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/timer.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/kernel/timer.c b/kernel/timer.c
index 611a5973d9e1..3b79da2f9c67 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1461,6 +1461,19 @@ void run_local_timers(void)
 	 * the timer softirq.
 	 */
 #ifdef CONFIG_PREEMPT_RT_FULL
+
+#ifndef CONFIG_SMP
+	/*
+	 * The spin_do_trylock() later may fail as the lock may be hold before
+	 * the interrupt arrived. The spin-lock debugging code will raise a
+	 * warning if the try_lock fails on UP. Since this is only an
+	 * optimization for the FULL_NO_HZ case (not to run the timer softirq on
+	 * an nohz_full CPU) we don't really care and shedule the softirq.
+	 */
+	raise_softirq(TIMER_SOFTIRQ);
+	return;
+#endif
+
 	/* On RT, irq work runs from softirq */
 	if (irq_work_needs_cpu()) {
 		raise_softirq(TIMER_SOFTIRQ);
-- 
2.0.0

[PATCH RT 3/4] Fix latency histogram after "hrtimer: Set expiry time before switch_hrtimer_base()"

[Steven Rostedt]

[-- Attachment #1: 0003-Fix-latency-histogram-after-hrtimer-Set-expiry-time-.patch --]
[-- Type: text/plain, Size: 1450 bytes --]

3.12.22-rt35-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Ben Hutchings <ben@decadent.org.uk>

In an rt-kernel with CONFIG_MISSED_TIMER_OFFSETS_HIST enabled,
__hrtimer_start_range_ns() now crashes, as new_base is not assigned
before it is used.

Tested-by: Carsten Emde <C.Emde@osadl.org>
Cc: stable-rt@vger.kernel.org
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/hrtimer.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index bc0e47dc0a05..c967b718ab37 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1105,6 +1105,11 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
 #endif
 	}
 
+	hrtimer_set_expires_range_ns(timer, tim, delta_ns);
+
+	/* Switch the timer base, if necessary: */
+	new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
+
 #ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
 	{
 		ktime_t now = new_base->get_time();
@@ -1116,11 +1121,6 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
 	}
 #endif
 
-	hrtimer_set_expires_range_ns(timer, tim, delta_ns);
-
-	/* Switch the timer base, if necessary: */
-	new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
-
 	timer_stats_hrtimer_set_start_info(timer);
 
 	leftmost = enqueue_hrtimer(timer, new_base);
-- 
2.0.0

[PATCH RT 4/4] Linux 3.12.22-rt35-rc1

[Steven Rostedt]

[-- Attachment #1: 0004-Linux-3.12.22-rt35-rc1.patch --]
[-- Type: text/plain, Size: 412 bytes --]

3.12.22-rt35-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>

---
 localversion-rt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/localversion-rt b/localversion-rt
index 21988f9ad53f..87569d22628e 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt34
+-rt35-rc1
-- 
2.0.0

Re: [PATCH RT 0/4] Linux 3.12.22-rt35-rc1

[Mike Galbraith]

On Wed, 2014-07-02 at 13:14 -0400, Steven Rostedt wrote: 
> Dear RT Folks,
> 
> This is the RT stable review cycle of patch 3.12.22-rt35-rc1.
> 
> Please scream at me if I messed something up. Please test the patches too.

[PATCH RT 5/4] sched: Do not clear PF_NO_SETAFFINITY flag in select_fallback_rq() ?

-Mike

Re: [PATCH RT 0/4] Linux 3.12.22-rt35-rc1

[Steven Rostedt]

On Thu, 03 Jul 2014 07:28:46 +0200
Mike Galbraith <umgwanakikbuti@gmail.com> wrote:

> 
> On Wed, 2014-07-02 at 13:14 -0400, Steven Rostedt wrote: 
> > Dear RT Folks,
> > 
> > This is the RT stable review cycle of patch 3.12.22-rt35-rc1.
> > 
> > Please scream at me if I messed something up. Please test the patches too.
> 
> [PATCH RT 5/4] sched: Do not clear PF_NO_SETAFFINITY flag in select_fallback_rq() ?
> 

Is that in 3.14-rt yet? I didn't see it. As with stable mainline,
nothing goes into stable-rt until it is in -rt upstream.

-- Steve

Re: [PATCH RT 0/4] Linux 3.12.22-rt35-rc1

[Mike Galbraith]

On Thu, 2014-07-03 at 08:39 -0400, Steven Rostedt wrote: 
> On Thu, 03 Jul 2014 07:28:46 +0200
> Mike Galbraith <umgwanakikbuti@gmail.com> wrote:
> 
> > 
> > On Wed, 2014-07-02 at 13:14 -0400, Steven Rostedt wrote: 
> > > Dear RT Folks,
> > > 
> > > This is the RT stable review cycle of patch 3.12.22-rt35-rc1.
> > > 
> > > Please scream at me if I messed something up. Please test the patches too.
> > 
> > [PATCH RT 5/4] sched: Do not clear PF_NO_SETAFFINITY flag in select_fallback_rq() ?
> > 
> 
> Is that in 3.14-rt yet? I didn't see it. As with stable mainline,
> nothing goes into stable-rt until it is in -rt upstream.

Oh right, no, not yet.

-Mike