| Subject: mm: page_alloc: Use local_lock_on() instead of plain spinlock |
| From: Thomas Gleixner <tglx@linutronix.de> |
| Date: Thu, 27 Sep 2012 11:11:46 +0200 |
| |
| The plain spinlock while sufficient does not update the local_lock |
| internals. Use a proper local_lock function instead to ease debugging. |
| |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| Cc: stable-rt@vger.kernel.org |
| --- |
| include/linux/locallock.h | 11 +++++++++++ |
| mm/page_alloc.c | 4 ++-- |
| 2 files changed, 13 insertions(+), 2 deletions(-) |
| |
| --- a/include/linux/locallock.h |
| +++ b/include/linux/locallock.h |
| @@ -137,6 +137,12 @@ static inline int __local_lock_irqsave(s |
| _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) |
| { |
| @@ -156,6 +162,11 @@ static inline int __local_unlock_irqrest |
| 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; \ |
| --- a/mm/page_alloc.c |
| +++ b/mm/page_alloc.c |
| @@ -224,9 +224,9 @@ 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) |