diff options
| author | Ingo Molnar <mingo@elte.hu> | 2005-01-19 23:28:52 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-01-19 23:28:52 -0800 |
| commit | 8522703fd856bebf42b41df1430632ffcdb8a705 (patch) | |
| tree | 84efcdd3f1112e93f71b84b9d0197f8e1529c5ed /kernel/spinlock.c | |
| parent | 8edee05783bfca65fb395f829fe74705047d65f9 (diff) | |
[PATCH] nonintrusive spin-polling loop in kernel/spinlock.c
This re-implements the nonintrusive spin-polling loop for the
SMP+PREEMPT spinlock/rwlock variants, using the new *_can_lock()
primitives. (The patch also adds *_can_lock() to the UP branch of
spinlock.h, for completeness.)
build- and boot-tested on x86 SMP+PREEMPT and SMP+!PREEMPT.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/spinlock.c')
| -rw-r--r-- | kernel/spinlock.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/kernel/spinlock.c b/kernel/spinlock.c index b485593430ec..b8e76ca8a001 100644 --- a/kernel/spinlock.c +++ b/kernel/spinlock.c @@ -174,7 +174,7 @@ EXPORT_SYMBOL(_write_lock); */ #define BUILD_LOCK_OPS(op, locktype) \ -void __lockfunc _##op##_lock(locktype *lock) \ +void __lockfunc _##op##_lock(locktype##_t *lock) \ { \ preempt_disable(); \ for (;;) { \ @@ -183,14 +183,15 @@ void __lockfunc _##op##_lock(locktype *lock) \ preempt_enable(); \ if (!(lock)->break_lock) \ (lock)->break_lock = 1; \ - cpu_relax(); \ + while (!op##_can_lock(lock) && (lock)->break_lock) \ + cpu_relax(); \ preempt_disable(); \ } \ } \ \ EXPORT_SYMBOL(_##op##_lock); \ \ -unsigned long __lockfunc _##op##_lock_irqsave(locktype *lock) \ +unsigned long __lockfunc _##op##_lock_irqsave(locktype##_t *lock) \ { \ unsigned long flags; \ \ @@ -204,7 +205,8 @@ unsigned long __lockfunc _##op##_lock_irqsave(locktype *lock) \ preempt_enable(); \ if (!(lock)->break_lock) \ (lock)->break_lock = 1; \ - cpu_relax(); \ + while (!op##_can_lock(lock) && (lock)->break_lock) \ + cpu_relax(); \ preempt_disable(); \ } \ return flags; \ @@ -212,14 +214,14 @@ unsigned long __lockfunc _##op##_lock_irqsave(locktype *lock) \ \ EXPORT_SYMBOL(_##op##_lock_irqsave); \ \ -void __lockfunc _##op##_lock_irq(locktype *lock) \ +void __lockfunc _##op##_lock_irq(locktype##_t *lock) \ { \ _##op##_lock_irqsave(lock); \ } \ \ EXPORT_SYMBOL(_##op##_lock_irq); \ \ -void __lockfunc _##op##_lock_bh(locktype *lock) \ +void __lockfunc _##op##_lock_bh(locktype##_t *lock) \ { \ unsigned long flags; \ \ @@ -244,9 +246,9 @@ EXPORT_SYMBOL(_##op##_lock_bh) * _[spin|read|write]_lock_irqsave() * _[spin|read|write]_lock_bh() */ -BUILD_LOCK_OPS(spin, spinlock_t); -BUILD_LOCK_OPS(read, rwlock_t); -BUILD_LOCK_OPS(write, rwlock_t); +BUILD_LOCK_OPS(spin, spinlock); +BUILD_LOCK_OPS(read, rwlock); +BUILD_LOCK_OPS(write, rwlock); #endif /* CONFIG_PREEMPT */ |