[PATCH 2/2] sched: Move the sleeping while atomic checks early in cond_resched()

From: Frederic Weisbecker
Date: Fri Jul 10 2009 - 10:50:27 EST


might_sleep() is called lately in cond_resched(), after the
need_resched()/preempt enabled/system running tests are checked.

It's better to check the sleeps while atomic earlier and not depend
on some environment datas that reduce the chances to detect a
problem.

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
---
include/linux/sched.h | 2 ++
kernel/sched.c | 3 ---
2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 0cb0d8d..e357dc7 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2279,11 +2279,13 @@ extern int _cond_resched(void);
#ifdef CONFIG_PREEMPT_BKL
static inline int cond_resched(void)
{
+ might_sleep();
return 0;
}
#else
static inline int cond_resched(void)
{
+ might_sleep();
return _cond_resched();
}
#endif
diff --git a/kernel/sched.c b/kernel/sched.c
index 87ecac1..c22804b 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -6605,9 +6605,6 @@ SYSCALL_DEFINE0(sched_yield)

static void __cond_resched(void)
{
-#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
- __might_sleep(__FILE__, __LINE__);
-#endif
/*
* The BKS might be reacquired before we have dropped
* PREEMPT_ACTIVE, which could trigger a second
--
1.6.2.3

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