[ANNOUNCE] 3.0.45-rt68

[ANNOUNCE] 3.0.45-rt68

[Steven Rostedt]

Dear RT Folks,

I'm pleased to announce the 3.0.45-rt68 stable release.


You can get this release via the git tree at:

  git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

  Head SHA1: 5df08aeb90f542384bd1c362ff8608f3d39503d5


Or to build 3.0.45-rt68 directly, the following patches should be applied:

  http://www.kernel.org/pub/linux/kernel/v3.0/linux-3.0.tar.xz

  http://www.kernel.org/pub/linux/kernel/v3.0/patch-3.0.45.xz

  http://www.kernel.org/pub/linux/kernel/projects/rt/3.0/patch-3.0.45-rt68.patch.xz


You can also build from 3.0.45-rt67 by applying the incremental patch:

  http://www.kernel.org/pub/linux/kernel/projects/rt/3.0/incr/patch-3.0.45-rt67-rt68.patch.xz



Enjoy,

-- Steve


Changes from 3.0.45-rt67:

---

Steven Rostedt (2):
      softirq: Init softirq local lock after per cpu section is set up
      Linux 3.0.45-rt68

Thomas Gleixner (4):
      mm: slab: Fix potential deadlock
      mm: page_alloc: Use local_lock_on() instead of plain spinlock
      rt: rwsem/rwlock: lockdep annotations
      sched: Better debug output for might sleep

----
 include/linux/locallock.h |   19 +++++++++++++++++++
 include/linux/sched.h     |    4 ++++
 init/main.c               |    2 +-
 kernel/rt.c               |   46 ++++++++++++++++++++++++---------------------
 kernel/sched.c            |   23 +++++++++++++++++++++--
 localversion-rt           |    2 +-
 mm/page_alloc.c           |    4 ++--
 mm/slab.c                 |   10 ++--------
 8 files changed, 75 insertions(+), 35 deletions(-)
---------------------------
diff --git a/include/linux/locallock.h b/include/linux/locallock.h
index 8fbc393..f1804a3 100644
--- a/include/linux/locallock.h
+++ b/include/linux/locallock.h
@@ -96,6 +96,9 @@ static inline void __local_lock_irq(struct local_irq_lock *lv)
 #define local_lock_irq(lvar)						\
 	do { __local_lock_irq(&get_local_var(lvar)); } while (0)
 
+#define local_lock_irq_on(lvar, cpu)					\
+	do { __local_lock_irq(&per_cpu(lvar, cpu)); } while (0)
+
 static inline void __local_unlock_irq(struct local_irq_lock *lv)
 {
 	LL_WARN(!lv->nestcnt);
@@ -111,6 +114,11 @@ static inline void __local_unlock_irq(struct local_irq_lock *lv)
 		put_local_var(lvar);					\
 	} while (0)
 
+#define local_unlock_irq_on(lvar, cpu)					\
+	do {								\
+		__local_unlock_irq(&per_cpu(lvar, cpu));		\
+	} while (0)
+
 static inline int __local_lock_irqsave(struct local_irq_lock *lv)
 {
 	if (lv->owner != current) {
@@ -129,6 +137,12 @@ static inline int __local_lock_irqsave(struct local_irq_lock *lv)
 		_flags = __get_cpu_var(lvar).flags;			\
 	} while (0)
 
+#define local_lock_irqsave_on(lvar, _flags, cpu)			\
+	do {								\
+		__local_lock_irqsave(&per_cpu(lvar, cpu));		\
+		_flags = per_cpu(lvar, cpu).flags;			\
+	} while (0)
+
 static inline int __local_unlock_irqrestore(struct local_irq_lock *lv,
 					    unsigned long flags)
 {
@@ -148,6 +162,11 @@ static inline int __local_unlock_irqrestore(struct local_irq_lock *lv,
 			put_local_var(lvar);				\
 	} while (0)
 
+#define local_unlock_irqrestore_on(lvar, flags, cpu)			\
+	do {								\
+		__local_unlock_irqrestore(&per_cpu(lvar, cpu), flags);	\
+	} while (0)
+
 #define local_spin_trylock_irq(lvar, lock)				\
 	({								\
 		int __locked;						\
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8155129..a179dd0 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1606,6 +1606,10 @@ struct task_struct {
 	int kmap_idx;
 	pte_t kmap_pte[KM_TYPE_NR];
 #endif
+
+#ifdef CONFIG_DEBUG_PREEMPT
+	unsigned long preempt_disable_ip;
+#endif
 };
 
 #ifdef CONFIG_PREEMPT_RT_FULL
diff --git a/init/main.c b/init/main.c
index 2713360..2f96fad 100644
--- a/init/main.c
+++ b/init/main.c
@@ -490,6 +490,7 @@ asmlinkage void __init start_kernel(void)
 	setup_command_line(command_line);
 	setup_nr_cpu_ids();
 	setup_per_cpu_areas();
+	softirq_early_init();
 	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
 
 	build_all_zonelists(NULL);
@@ -500,7 +501,6 @@ asmlinkage void __init start_kernel(void)
 	parse_args("Booting kernel", static_command_line, __start___param,
 		   __stop___param - __start___param,
 		   &unknown_bootoption);
-	softirq_early_init();
 	/*
 	 * These use large bootmem allocations and must precede
 	 * kmem_cache_init()
diff --git a/kernel/rt.c b/kernel/rt.c
index 092d6b3..aa10504 100644
--- a/kernel/rt.c
+++ b/kernel/rt.c
@@ -216,15 +216,17 @@ int __lockfunc rt_read_trylock(rwlock_t *rwlock)
 	 * write locked.
 	 */
 	migrate_disable();
-	if (rt_mutex_owner(lock) != current)
+	if (rt_mutex_owner(lock) != current) {
 		ret = rt_mutex_trylock(lock);
-	else if (!rwlock->read_depth)
+		if (ret)
+			rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
+	} else if (!rwlock->read_depth) {
 		ret = 0;
+	}
 
-	if (ret) {
+	if (ret)
 		rwlock->read_depth++;
-		rwlock_acquire_read(&rwlock->dep_map, 0, 1, _RET_IP_);
-	} else
+	else
 		migrate_enable();
 
 	return ret;
@@ -242,13 +244,13 @@ void __lockfunc rt_read_lock(rwlock_t *rwlock)
 {
 	struct rt_mutex *lock = &rwlock->lock;
 
-	rwlock_acquire_read(&rwlock->dep_map, 0, 0, _RET_IP_);
-
 	/*
 	 * recursive read locks succeed when current owns the lock
 	 */
-	if (rt_mutex_owner(lock) != current)
+	if (rt_mutex_owner(lock) != current) {
+		rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
 		__rt_spin_lock(lock);
+	}
 	rwlock->read_depth++;
 }
 
@@ -264,11 +266,11 @@ EXPORT_SYMBOL(rt_write_unlock);
 
 void __lockfunc rt_read_unlock(rwlock_t *rwlock)
 {
-	rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
-
 	/* Release the lock only when read_depth is down to 0 */
-	if (--rwlock->read_depth == 0)
+	if (--rwlock->read_depth == 0) {
+		rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
 		__rt_spin_unlock(&rwlock->lock);
+	}
 }
 EXPORT_SYMBOL(rt_read_unlock);
 
@@ -315,9 +317,10 @@ EXPORT_SYMBOL(rt_up_write);
 
 void  rt_up_read(struct rw_semaphore *rwsem)
 {
-	rwsem_release(&rwsem->dep_map, 1, _RET_IP_);
-	if (--rwsem->read_depth == 0)
+	if (--rwsem->read_depth == 0) {
+		rwsem_release(&rwsem->dep_map, 1, _RET_IP_);
 		rt_mutex_unlock(&rwsem->lock);
+	}
 }
 EXPORT_SYMBOL(rt_up_read);
 
@@ -366,15 +369,16 @@ int  rt_down_read_trylock(struct rw_semaphore *rwsem)
 	 * but not when read_depth == 0 which means that the rwsem is
 	 * write locked.
 	 */
-	if (rt_mutex_owner(lock) != current)
+	if (rt_mutex_owner(lock) != current) {
 		ret = rt_mutex_trylock(&rwsem->lock);
-	else if (!rwsem->read_depth)
+		if (ret)
+			rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_);
+	} else if (!rwsem->read_depth) {
 		ret = 0;
+	}
 
-	if (ret) {
+	if (ret)
 		rwsem->read_depth++;
-		rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_);
-	}
 	return ret;
 }
 EXPORT_SYMBOL(rt_down_read_trylock);
@@ -383,10 +387,10 @@ static void __rt_down_read(struct rw_semaphore *rwsem, int subclass)
 {
 	struct rt_mutex *lock = &rwsem->lock;
 
-	rwsem_acquire_read(&rwsem->dep_map, subclass, 0, _RET_IP_);
-
-	if (rt_mutex_owner(lock) != current)
+	if (rt_mutex_owner(lock) != current) {
+		rwsem_acquire(&rwsem->dep_map, subclass, 0, _RET_IP_);
 		rt_mutex_lock(&rwsem->lock);
+	}
 	rwsem->read_depth++;
 }
 
diff --git a/kernel/sched.c b/kernel/sched.c
index ea235b6..38f9104 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4121,8 +4121,13 @@ void __kprobes add_preempt_count(int val)
 	DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
 				PREEMPT_MASK - 10);
 #endif
-	if (preempt_count() == val)
-		trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+	if (preempt_count() == val) {
+		unsigned long ip = get_parent_ip(CALLER_ADDR1);
+#ifdef CONFIG_DEBUG_PREEMPT
+		current->preempt_disable_ip = ip;
+#endif
+		trace_preempt_off(CALLER_ADDR0, ip);
+	}
 }
 EXPORT_SYMBOL(add_preempt_count);
 
@@ -4164,6 +4169,13 @@ static noinline void __schedule_bug(struct task_struct *prev)
 	print_modules();
 	if (irqs_disabled())
 		print_irqtrace_events(prev);
+#ifdef DEBUG_PREEMPT
+	if (in_atomic_preempt_off()) {
+		pr_err("Preemption disabled at:");
+		print_ip_sym(current->preempt_disable_ip);
+		pr_cont("\n");
+	}
+#endif
 
 	if (regs)
 		show_regs(regs);
@@ -8483,6 +8495,13 @@ void __might_sleep(const char *file, int line, int preempt_offset)
 	debug_show_held_locks(current);
 	if (irqs_disabled())
 		print_irqtrace_events(current);
+#ifdef DEBUG_PREEMPT
+	if (!preempt_count_equals(preempt_offset)) {
+		pr_err("Preemption disabled at:");
+		print_ip_sym(current->preempt_disable_ip);
+		pr_cont("\n");
+	}
+#endif
 	dump_stack();
 #endif
 }
diff --git a/localversion-rt b/localversion-rt
index 5513b84..df2c52c 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt67
+-rt68
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 47d939e..c645e07 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -227,9 +227,9 @@ static DEFINE_LOCAL_IRQ_LOCK(pa_lock);
 
 #ifdef CONFIG_PREEMPT_RT_BASE
 # define cpu_lock_irqsave(cpu, flags)		\
-	spin_lock_irqsave(&per_cpu(pa_lock, cpu).lock, flags)
+	local_lock_irqsave_on(pa_lock, flags, cpu)
 # define cpu_unlock_irqrestore(cpu, flags)		\
-	spin_unlock_irqrestore(&per_cpu(pa_lock, cpu).lock, flags)
+	local_unlock_irqrestore_on(pa_lock, flags, cpu)
 #else
 # define cpu_lock_irqsave(cpu, flags)		local_irq_save(flags)
 # define cpu_unlock_irqrestore(cpu, flags)	local_irq_restore(flags)
diff --git a/mm/slab.c b/mm/slab.c
index f451650..d7cdccb 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -745,18 +745,12 @@ slab_on_each_cpu(void (*func)(void *arg, int this_cpu), void *arg)
 
 static void lock_slab_on(unsigned int cpu)
 {
-	if (cpu == smp_processor_id())
-		local_lock_irq(slab_lock);
-	else
-		local_spin_lock_irq(slab_lock, &per_cpu(slab_lock, cpu).lock);
+	local_lock_irq_on(slab_lock, cpu);
 }
 
 static void unlock_slab_on(unsigned int cpu)
 {
-	if (cpu == smp_processor_id())
-		local_unlock_irq(slab_lock);
-	else
-		local_spin_unlock_irq(slab_lock, &per_cpu(slab_lock, cpu).lock);
+	local_unlock_irq_on(slab_lock, cpu);
 }
 #endif
 

[ANNOUNCE] 3.0.45-rt68

[Steven Rostedt]

Dear RT Folks,

I'm pleased to announce the 3.0.45-rt68 stable release.


This release is just an update to the new stable 3.0.45 version
and no RT specific changes have been made.


You can get this release via the git tree at:

  git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

  Head SHA1: ec0eb0e2dca4005fcf984d3f1b67511b43d546fb


Or to build 3.0.45-rt68 directly, the following patches should be applied:

  http://www.kernel.org/pub/linux/kernel/v3.0/linux-3.0.tar.xz

  http://www.kernel.org/pub/linux/kernel/v3.0/patch-3.0.45.xz

  http://www.kernel.org/pub/linux/kernel/projects/rt/3.0/patch-3.0.45-rt68.patch.xz



Enjoy,

-- Steve