diff options
| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2006-09-30 23:27:45 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-01 00:39:22 -0700 |
| commit | 3c1fcfe229e99752c74efb945a4a3f560be04204 (patch) | |
| tree | 44085d9b599e06a92426141811a6f712beac17aa /include/asm-s390/spinlock.h | |
| parent | cdc39363d33506b0e067d41fc91f89d186bdf7f7 (diff) | |
[PATCH] Directed yield: direct yield of spinlocks for s390.
Use the new diagnose 0x9c in the spinlock implementation for s390. It
yields the remaining timeslice of the virtual cpu that tries to acquire a
lock to the virtual cpu that is the current holder of the lock.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/asm-s390/spinlock.h')
| -rw-r--r-- | include/asm-s390/spinlock.h | 33 |
1 files changed, 23 insertions, 10 deletions
diff --git a/include/asm-s390/spinlock.h b/include/asm-s390/spinlock.h index 5f00feaf1be6..6b78af16999b 100644 --- a/include/asm-s390/spinlock.h +++ b/include/asm-s390/spinlock.h @@ -13,6 +13,8 @@ #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2) +#include <linux/smp.h> + static inline int _raw_compare_and_swap(volatile unsigned int *lock, unsigned int old, unsigned int new) @@ -50,34 +52,46 @@ _raw_compare_and_swap(volatile unsigned int *lock, * (the type definitions are in asm/spinlock_types.h) */ -#define __raw_spin_is_locked(x) ((x)->lock != 0) +#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)) cpu_relax(); } while (0) + do { while (__raw_spin_is_locked(lock)) \ + _raw_spin_relax(lock); } while (0) -extern void _raw_spin_lock_wait(raw_spinlock_t *lp, unsigned int pc); -extern int _raw_spin_trylock_retry(raw_spinlock_t *lp, unsigned int pc); +extern void _raw_spin_lock_wait(raw_spinlock_t *, unsigned int pc); +extern int _raw_spin_trylock_retry(raw_spinlock_t *, unsigned int pc); +extern void _raw_spin_relax(raw_spinlock_t *lock); static inline void __raw_spin_lock(raw_spinlock_t *lp) { unsigned long pc = 1 | (unsigned long) __builtin_return_address(0); - - if (unlikely(_raw_compare_and_swap(&lp->lock, 0, pc) != 0)) - _raw_spin_lock_wait(lp, pc); + int old; + + old = _raw_compare_and_swap(&lp->owner_cpu, 0, ~smp_processor_id()); + if (likely(old == 0)) { + lp->owner_pc = pc; + return; + } + _raw_spin_lock_wait(lp, pc); } static inline int __raw_spin_trylock(raw_spinlock_t *lp) { unsigned long pc = 1 | (unsigned long) __builtin_return_address(0); + int old; - if (likely(_raw_compare_and_swap(&lp->lock, 0, pc) == 0)) + old = _raw_compare_and_swap(&lp->owner_cpu, 0, ~smp_processor_id()); + if (likely(old == 0)) { + lp->owner_pc = pc; return 1; + } return _raw_spin_trylock_retry(lp, pc); } static inline void __raw_spin_unlock(raw_spinlock_t *lp) { - _raw_compare_and_swap(&lp->lock, lp->lock, 0); + lp->owner_pc = 0; + _raw_compare_and_swap(&lp->owner_cpu, lp->owner_cpu, 0); } /* @@ -154,7 +168,6 @@ static inline int __raw_write_trylock(raw_rwlock_t *rw) return _raw_write_trylock_retry(rw); } -#define _raw_spin_relax(lock) cpu_relax() #define _raw_read_relax(lock) cpu_relax() #define _raw_write_relax(lock) cpu_relax() |