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| author | Robin Holt <holt@sgi.com> | 2009-04-03 01:59:45 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-04-03 04:05:10 +0200 |
| commit | e8c158bb313c1df421eab7dc4299cd39cbbf5895 (patch) | |
| tree | 8a5f1d01e58d0e358b2b0c9407fc494912e83c27 /kernel/spinlock.c | |
| parent | fs/ufs: return f_fsid for statfs(2) (diff) | |
| download | linux-e8c158bb313c1df421eab7dc4299cd39cbbf5895.tar.xz linux-e8c158bb313c1df421eab7dc4299cd39cbbf5895.zip | |
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 <ptesarik@suse.cz>
Signed-off-by: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/spinlock.c')
| -rw-r--r-- | kernel/spinlock.c | 12 |
1 files changed, 2 insertions, 10 deletions
diff --git a/kernel/spinlock.c b/kernel/spinlock.c index 29ab20749dd3..7283c6dc2d59 100644 --- a/kernel/spinlock.c +++ b/kernel/spinlock.c @@ -299,16 +299,8 @@ unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclas local_irq_save(flags); preempt_disable(); spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_); - /* - * On lockdep we dont want the hand-coded irq-enable of - * _raw_spin_lock_flags() code, because lockdep assumes - * that interrupts are not re-enabled during lock-acquire: - */ -#ifdef CONFIG_LOCKDEP - LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock); -#else - _raw_spin_lock_flags(lock, &flags); -#endif + LOCK_CONTENDED_FLAGS(lock, _raw_spin_trylock, _raw_spin_lock, + _raw_spin_lock_flags, &flags); return flags; } EXPORT_SYMBOL(_spin_lock_irqsave_nested); |