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authorFrederic Weisbecker <fweisbec@gmail.com>2009-07-16 15:44:29 +0200
committerIngo Molnar <mingo@elte.hu>2009-07-18 15:51:44 +0200
commit613afbf83298efaead05ebcac23d2285609d7160 (patch)
tree15fa2025d74cee5f6805ab974c532c6b6a603333
parent6f80bd985fe242c2e6a8b6209ed20b0495d3d63b (diff)
downloadop-kernel-dev-613afbf83298efaead05ebcac23d2285609d7160.zip
op-kernel-dev-613afbf83298efaead05ebcac23d2285609d7160.tar.gz
sched: Pull up the might_sleep() check into cond_resched()
might_sleep() is called late-ish 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. Also define cond_resched_*() helpers as macros, so that the FILE/LINE reported in the sleeping while atomic warning displays the real origin and not sched.h Changes in v2: - Call __might_sleep() directly instead of might_sleep() which may call cond_resched() - Turn cond_resched() into a macro so that the file:line couple reported refers to the caller of cond_resched() and not __cond_resched() itself. Changes in v3: - Also propagate this __might_sleep() pull up to cond_resched_lock() and cond_resched_softirq() Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-6-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--fs/dcache.c1
-rw-r--r--include/linux/sched.h29
-rw-r--r--kernel/sched.c12
3 files changed, 25 insertions, 17 deletions
diff --git a/fs/dcache.c b/fs/dcache.c
index 9e5cd3c..a100fa3 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -32,6 +32,7 @@
#include <linux/swap.h>
#include <linux/bootmem.h>
#include <linux/fs_struct.h>
+#include <linux/hardirq.h>
#include "internal.h"
int sysctl_vfs_cache_pressure __read_mostly = 100;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index e2bdf18..c41d424 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2286,17 +2286,26 @@ static inline int need_resched(void)
*/
extern int _cond_resched(void);
-static inline int cond_resched(void)
-{
- return _cond_resched();
-}
+#define cond_resched() ({ \
+ __might_sleep(__FILE__, __LINE__, 0); \
+ _cond_resched(); \
+})
-extern int cond_resched_lock(spinlock_t * lock);
-extern int cond_resched_softirq(void);
-static inline int cond_resched_bkl(void)
-{
- return _cond_resched();
-}
+extern int __cond_resched_lock(spinlock_t *lock);
+
+#define cond_resched_lock(lock) ({ \
+ __might_sleep(__FILE__, __LINE__, PREEMPT_OFFSET); \
+ __cond_resched_lock(lock); \
+})
+
+extern int __cond_resched_softirq(void);
+
+#define cond_resched_softirq() ({ \
+ __might_sleep(__FILE__, __LINE__, SOFTIRQ_OFFSET); \
+ __cond_resched_softirq(); \
+})
+
+#define cond_resched_bkl() cond_resched()
/*
* Does a critical section need to be broken due to another
diff --git a/kernel/sched.c b/kernel/sched.c
index 3ff4d00..1f7919a 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -6610,8 +6610,6 @@ static inline int should_resched(void)
static void __cond_resched(void)
{
- __might_sleep(__FILE__, __LINE__, 0);
-
add_preempt_count(PREEMPT_ACTIVE);
schedule();
sub_preempt_count(PREEMPT_ACTIVE);
@@ -6628,14 +6626,14 @@ int __sched _cond_resched(void)
EXPORT_SYMBOL(_cond_resched);
/*
- * cond_resched_lock() - if a reschedule is pending, drop the given lock,
+ * __cond_resched_lock() - if a reschedule is pending, drop the given lock,
* call schedule, and on return reacquire the lock.
*
* This works OK both with and without CONFIG_PREEMPT. We do strange low-level
* operations here to prevent schedule() from being called twice (once via
* spin_unlock(), once by hand).
*/
-int cond_resched_lock(spinlock_t *lock)
+int __cond_resched_lock(spinlock_t *lock)
{
int resched = should_resched();
int ret = 0;
@@ -6651,9 +6649,9 @@ int cond_resched_lock(spinlock_t *lock)
}
return ret;
}
-EXPORT_SYMBOL(cond_resched_lock);
+EXPORT_SYMBOL(__cond_resched_lock);
-int __sched cond_resched_softirq(void)
+int __sched __cond_resched_softirq(void)
{
BUG_ON(!in_softirq());
@@ -6665,7 +6663,7 @@ int __sched cond_resched_softirq(void)
}
return 0;
}
-EXPORT_SYMBOL(cond_resched_softirq);
+EXPORT_SYMBOL(__cond_resched_softirq);
/**
* yield - yield the current processor to other threads.
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