From 3b4beb31759765efdda9f9431aebfedf828bbfe0 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Sat, 26 Jan 2008 14:11:03 +0100 Subject: [S390] Remove owner_pc member from raw_spinlock_t. Used to contain the address of the holder of the lock. But since the spinlock code is not inlined anymore all locks contain the same address anyway. And since in addtition nobody complained about that for ages its obviously unused. So remove it. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/lib/spinlock.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'arch/s390/lib/spinlock.c') diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c index 8d76403fcf89..59c56c3d72d0 100644 --- a/arch/s390/lib/spinlock.c +++ b/arch/s390/lib/spinlock.c @@ -39,7 +39,7 @@ static inline void _raw_yield_cpu(int cpu) _raw_yield(); } -void _raw_spin_lock_wait(raw_spinlock_t *lp, unsigned int pc) +void _raw_spin_lock_wait(raw_spinlock_t *lp) { int count = spin_retry; unsigned int cpu = ~smp_processor_id(); @@ -53,15 +53,13 @@ void _raw_spin_lock_wait(raw_spinlock_t *lp, unsigned int pc) } if (__raw_spin_is_locked(lp)) continue; - if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0) { - lp->owner_pc = pc; + if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0) return; - } } } EXPORT_SYMBOL(_raw_spin_lock_wait); -int _raw_spin_trylock_retry(raw_spinlock_t *lp, unsigned int pc) +int _raw_spin_trylock_retry(raw_spinlock_t *lp) { unsigned int cpu = ~smp_processor_id(); int count; @@ -69,10 +67,8 @@ int _raw_spin_trylock_retry(raw_spinlock_t *lp, unsigned int pc) for (count = spin_retry; count > 0; count--) { if (__raw_spin_is_locked(lp)) continue; - if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0) { - lp->owner_pc = pc; + if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0) return 1; - } } return 0; } -- cgit v1.2.3 From 894cdde26b538c77b9943bc72f0570abf6e58e37 Mon Sep 17 00:00:00 2001 From: Hisashi Hifumi Date: Sat, 26 Jan 2008 14:11:28 +0100 Subject: [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 Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/lib/spinlock.c | 23 +++++++++++++++++++++++ include/asm-s390/spinlock.h | 13 ++++++++++++- 2 files changed, 35 insertions(+), 1 deletion(-) (limited to 'arch/s390/lib/spinlock.c') diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c index 59c56c3d72d0..e41f4008afc5 100644 --- a/arch/s390/lib/spinlock.c +++ b/arch/s390/lib/spinlock.c @@ -59,6 +59,29 @@ void _raw_spin_lock_wait(raw_spinlock_t *lp) } EXPORT_SYMBOL(_raw_spin_lock_wait); +void _raw_spin_lock_wait_flags(raw_spinlock_t *lp, unsigned long flags) +{ + int count = spin_retry; + unsigned int cpu = ~smp_processor_id(); + + local_irq_restore(flags); + while (1) { + if (count-- <= 0) { + unsigned int owner = lp->owner_cpu; + if (owner != 0) + _raw_yield_cpu(~owner); + count = spin_retry; + } + if (__raw_spin_is_locked(lp)) + continue; + local_irq_disable(); + if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0) + return; + local_irq_restore(flags); + } +} +EXPORT_SYMBOL(_raw_spin_lock_wait_flags); + int _raw_spin_trylock_retry(raw_spinlock_t *lp) { unsigned int cpu = ~smp_processor_id(); diff --git a/include/asm-s390/spinlock.h b/include/asm-s390/spinlock.h index c1d6e7e304e2..df84ae96915f 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; -- cgit v1.2.3