diff options
| author | Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp> | 2008-01-26 13:11:28 (GMT) |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-01-26 13:11:31 (GMT) |
| commit | 894cdde26b538c77b9943bc72f0570abf6e58e37 (patch) | |
| tree | 335f75460bd947c4969c9b7a1ec5764b98bf1d2b /include/asm-s390 | |
| parent | dab5209cd878c146d9f6923f061d1c2725ff210f (diff) | |
| download | linux-894cdde26b538c77b9943bc72f0570abf6e58e37.tar.xz | |
[S390] do local_irq_restore while spinning in spin_lock_irqsave.
In s390's spin_lock_irqsave, interrupts remain disabled while
spinning. In other architectures like x86 and powerpc, interrupts are
re-enabled while spinning if IRQ is not masked before spin_lock_irqsave
is called.
The following patch re-enables interrupts through local_irq_restore
while spinning for a lock acquisition.
This can improve system response.
[heiko.carstens@de.ibm.com: removed saving of pc]
Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'include/asm-s390')
| -rw-r--r-- | include/asm-s390/spinlock.h | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/include/asm-s390/spinlock.h b/include/asm-s390/spinlock.h index c1d6e7e..df84ae9 100644 --- a/include/asm-s390/spinlock.h +++ b/include/asm-s390/spinlock.h @@ -53,12 +53,12 @@ _raw_compare_and_swap(volatile unsigned int *lock, */ #define __raw_spin_is_locked(x) ((x)->owner_cpu != 0) -#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock) #define __raw_spin_unlock_wait(lock) \ do { while (__raw_spin_is_locked(lock)) \ _raw_spin_relax(lock); } while (0) extern void _raw_spin_lock_wait(raw_spinlock_t *); +extern void _raw_spin_lock_wait_flags(raw_spinlock_t *, unsigned long flags); extern int _raw_spin_trylock_retry(raw_spinlock_t *); extern void _raw_spin_relax(raw_spinlock_t *lock); @@ -72,6 +72,17 @@ static inline void __raw_spin_lock(raw_spinlock_t *lp) _raw_spin_lock_wait(lp); } +static inline void __raw_spin_lock_flags(raw_spinlock_t *lp, + unsigned long flags) +{ + int old; + + old = _raw_compare_and_swap(&lp->owner_cpu, 0, ~smp_processor_id()); + if (likely(old == 0)) + return; + _raw_spin_lock_wait_flags(lp, flags); +} + static inline int __raw_spin_trylock(raw_spinlock_t *lp) { int old; |