From e8c158bb313c1df421eab7dc4299cd39cbbf5895 Mon Sep 17 00:00:00 2001 From: Robin Holt Date: Thu, 2 Apr 2009 16:59:45 -0700 Subject: Factor out #ifdefs from kernel/spinlock.c to LOCK_CONTENDED_FLAGS SGI has observed that on large systems, interrupts are not serviced for a long period of time when waiting for a rwlock. The following patch series re-enables irqs while waiting for the lock, resembling the code which is already there for spinlocks. I only made the ia64 version, because the patch adds some overhead to the fast path. I assume there is currently no demand to have this for other architectures, because the systems are not so large. Of course, the possibility to implement raw_{read|write}_lock_flags for any architecture is still there. This patch: The new macro LOCK_CONTENDED_FLAGS expands to the correct implementation depending on the config options, so that IRQ's are re-enabled when possible, but they remain disabled if CONFIG_LOCKDEP is set. Signed-off-by: Petr Tesarik Signed-off-by: Robin Holt Cc: Cc: Ingo Molnar Cc: Peter Zijlstra Cc: "Luck, Tony" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/lockdep.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'include/linux/lockdep.h') diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 5a58ea3e91e..da5a5a1f4cd 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -364,6 +364,23 @@ do { \ #endif /* CONFIG_LOCK_STAT */ +#ifdef CONFIG_LOCKDEP + +/* + * On lockdep we dont want the hand-coded irq-enable of + * _raw_*_lock_flags() code, because lockdep assumes + * that interrupts are not re-enabled during lock-acquire: + */ +#define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \ + LOCK_CONTENDED((_lock), (try), (lock)) + +#else /* CONFIG_LOCKDEP */ + +#define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \ + lockfl((_lock), (flags)) + +#endif /* CONFIG_LOCKDEP */ + #ifdef CONFIG_GENERIC_HARDIRQS extern void early_init_irq_lock_class(void); #else -- cgit v1.2.3