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 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (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(); -- cgit v1.2.3