diff options
| author | Samuel Thibault <samuel.thibault@labri.fr> | 2005-05-21 17:50:15 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-05-21 10:46:48 -0700 |
| commit | 10f02d1c59e55f529140dda3a92f0099d748451c (patch) | |
| tree | 6b5a5804503401624171aff65b09ff022a9f0103 | |
| parent | 9636273dae265b9354b861b373cd43cd76a6d0fe (diff) | |
[PATCH] spin_unlock_bh() and preempt_check_resched()
In _spin_unlock_bh(lock):
do { \
_raw_spin_unlock(lock); \
preempt_enable(); \
local_bh_enable(); \
__release(lock); \
} while (0)
there is no reason for using preempt_enable() instead of a simple
preempt_enable_no_resched()
Since we know bottom halves are disabled, preempt_schedule() will always
return at once (preempt_count!=0), and hence preempt_check_resched() is
useless here...
This fixes it by using "preempt_enable_no_resched()" instead of the
"preempt_enable()", and thus avoids the useless preempt_check_resched()
just before re-enabling bottom halves.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | include/linux/spinlock.h | 8 | ||||
| -rw-r--r-- | kernel/spinlock.c | 8 |
2 files changed, 8 insertions, 8 deletions
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index e895f3eaf53a..d6ba068719b6 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -248,7 +248,7 @@ typedef struct { #define _spin_trylock_bh(lock) ({preempt_disable(); local_bh_disable(); \ _raw_spin_trylock(lock) ? \ - 1 : ({preempt_enable(); local_bh_enable(); 0;});}) + 1 : ({preempt_enable_no_resched(); local_bh_enable(); 0;});}) #define _spin_lock(lock) \ do { \ @@ -383,7 +383,7 @@ do { \ #define _spin_unlock_bh(lock) \ do { \ _raw_spin_unlock(lock); \ - preempt_enable(); \ + preempt_enable_no_resched(); \ local_bh_enable(); \ __release(lock); \ } while (0) @@ -391,7 +391,7 @@ do { \ #define _write_unlock_bh(lock) \ do { \ _raw_write_unlock(lock); \ - preempt_enable(); \ + preempt_enable_no_resched(); \ local_bh_enable(); \ __release(lock); \ } while (0) @@ -423,8 +423,8 @@ do { \ #define _read_unlock_bh(lock) \ do { \ _raw_read_unlock(lock); \ + preempt_enable_no_resched(); \ local_bh_enable(); \ - preempt_enable(); \ __release(lock); \ } while (0) diff --git a/kernel/spinlock.c b/kernel/spinlock.c index e15ed17863f1..0c3f9d8bbe17 100644 --- a/kernel/spinlock.c +++ b/kernel/spinlock.c @@ -294,7 +294,7 @@ EXPORT_SYMBOL(_spin_unlock_irq); void __lockfunc _spin_unlock_bh(spinlock_t *lock) { _raw_spin_unlock(lock); - preempt_enable(); + preempt_enable_no_resched(); local_bh_enable(); } EXPORT_SYMBOL(_spin_unlock_bh); @@ -318,7 +318,7 @@ EXPORT_SYMBOL(_read_unlock_irq); void __lockfunc _read_unlock_bh(rwlock_t *lock) { _raw_read_unlock(lock); - preempt_enable(); + preempt_enable_no_resched(); local_bh_enable(); } EXPORT_SYMBOL(_read_unlock_bh); @@ -342,7 +342,7 @@ EXPORT_SYMBOL(_write_unlock_irq); void __lockfunc _write_unlock_bh(rwlock_t *lock) { _raw_write_unlock(lock); - preempt_enable(); + preempt_enable_no_resched(); local_bh_enable(); } EXPORT_SYMBOL(_write_unlock_bh); @@ -354,7 +354,7 @@ int __lockfunc _spin_trylock_bh(spinlock_t *lock) if (_raw_spin_trylock(lock)) return 1; - preempt_enable(); + preempt_enable_no_resched(); local_bh_enable(); return 0; } |