From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Carsten Emde <C.Emde@osadl.org>, John Kacur <jkacur@redhat.com>
Subject: [PATCH RT 4/8] mm: page_alloc: Use local_lock_on() instead of plain spinlock
Date: Thu, 11 Oct 2012 21:20:28 -0400 [thread overview]
Message-ID: <20121012012126.241147167@goodmis.org> (raw)
In-Reply-To: 20121012012024.056658930@goodmis.org
[-- Attachment #1: 0004-mm-page_alloc-Use-local_lock_on-instead-of-plain-spi.patch --]
[-- Type: text/plain, Size: 2088 bytes --]
From: Thomas Gleixner <tglx@linutronix.de>
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
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
include/linux/locallock.h | 11 +++++++++++
mm/page_alloc.c | 4 ++--
2 files changed, 13 insertions(+), 2 deletions(-)
diff --git a/include/linux/locallock.h b/include/linux/locallock.h
index 0161fbb..f1804a3 100644
--- a/include/linux/locallock.h
+++ b/include/linux/locallock.h
@@ -137,6 +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)
{
@@ -156,6 +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/mm/page_alloc.c b/mm/page_alloc.c
index 67202bc..8678a7f 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)
--
1.7.10.4
next prev parent reply other threads:[~2012-10-12 1:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-12 1:20 [PATCH RT 0/8] [ANNOUNCE] 3.2.31-rt47-rc1 stable review Steven Rostedt
2012-10-12 1:20 ` [PATCH RT 1/8] random: Make it work on rt Steven Rostedt
2012-10-12 1:20 ` [PATCH RT 2/8] softirq: Init softirq local lock after per cpu section is set up Steven Rostedt
2012-10-12 1:20 ` [PATCH RT 3/8] mm: slab: Fix potential deadlock Steven Rostedt
2012-10-12 1:20 ` Steven Rostedt [this message]
2012-10-12 1:20 ` [PATCH RT 5/8] rt: rwsem/rwlock: lockdep annotations Steven Rostedt
2012-10-12 1:20 ` [PATCH RT 6/8] sched: Better debug output for might sleep Steven Rostedt
2012-10-12 1:20 ` [PATCH RT 7/8] stomp_machine: Use mutex_trylock when called from inactive cpu Steven Rostedt
2012-10-12 1:20 ` [PATCH RT 8/8] Linux 3.2.31-rt47-rc1 Steven Rostedt
-- strict thread matches above, loose matches on Subject: below --
2012-10-10 13:34 [PATCH RT 0/8] [ANNOUNCE] 3.4.13-rt22-rc1 stable review Steven Rostedt
2012-10-10 13:34 ` [PATCH RT 4/8] mm: page_alloc: Use local_lock_on() instead of plain spinlock Steven Rostedt
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