[PATCH] spinlock: __raw_spin_is_locked() should return true for UP
[Posted August 19, 2009 by corbet]
| From: |
| Kumar Gala <galak-AT-kernel.crashing.org> |
| To: |
| Linus Torvalds <torvalds-AT-osdl.org> |
| Subject: |
| [PATCH] spinlock: __raw_spin_is_locked() should return true for UP |
| Date: |
| Tue, 18 Aug 2009 17:42:23 -0500 |
| Cc: |
| peterz-AT-infradead.org, linux-kernel-AT-vger.kernel.org, rostedt-AT-goodmis.org,
linuxppc-dev-AT-ozlabs.org, mingo-AT-elte.hu, tglx-AT-linutronix.de |
| Archive-link: |
| Article, Thread
|
For some reason __raw_spin_is_locked() has been returning false for the
uni-processor, non-CONFIG_DEBUG_SPINLOCK. The UP + CONFIG_DEBUG_SPINLOCK
handles this correctly.
Found this by enabling CONFIG_DEBUG_VM on PPC and hitting always hitting
a BUG_ON that was testing to make sure the pte_lock was held.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---
Linus, a fix for 2.6.31
include/linux/spinlock_up.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/include/linux/spinlock_up.h b/include/linux/spinlock_up.h
index d4841ed..2b372e0 100644
--- a/include/linux/spinlock_up.h
+++ b/include/linux/spinlock_up.h
@@ -57,7 +57,7 @@ static inline void __raw_spin_unlock(raw_spinlock_t *lock)
#define __raw_write_unlock(lock) do { (void)(lock); } while (0)
#else /* DEBUG_SPINLOCK */
-#define __raw_spin_is_locked(lock) ((void)(lock), 0)
+#define __raw_spin_is_locked(lock) ((void)(lock), 1)
/* for sched.c and kernel_lock.c: */
# define __raw_spin_lock(lock) do { (void)(lock); } while (0)
# define __raw_spin_lock_flags(lock, flags) do { (void)(lock); } while (0)
--
1.6.0.6
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