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authorAndrew Morton <akpm@osdl.org>2006-08-05 12:13:47 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-08-06 08:57:46 -0700
commit72f0b4e2133ba1d65147d06016c0b6d2202235ca (patch)
tree5e03d0c34379db77f50238c546f5417139ac9671
parent927cbe8a3e9ebc466f76af5a5278a520dc2d5699 (diff)
[PATCH] disable debugging version of write_lock()
We've confirmed that the debug version of write_lock() can get stuck for long enough to cause NMI watchdog timeouts and hence a crash. We don't know why, yet. Disable it for now. Also disable the similar read_lock() code. Just in case. Thanks to Dave Olson <olson@unixfolk.com> for reporting and testing. Acked-by: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--lib/spinlock_debug.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c
index 3d9c4dc965ed..58c577dd82e5 100644
--- a/lib/spinlock_debug.c
+++ b/lib/spinlock_debug.c
@@ -162,6 +162,7 @@ static void rwlock_bug(rwlock_t *lock, const char *msg)
#define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg)
+#if 0 /* __write_lock_debug() can lock up - maybe this can too? */
static void __read_lock_debug(rwlock_t *lock)
{
int print_once = 1;
@@ -184,12 +185,12 @@ static void __read_lock_debug(rwlock_t *lock)
}
}
}
+#endif
void _raw_read_lock(rwlock_t *lock)
{
RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
- if (unlikely(!__raw_read_trylock(&lock->raw_lock)))
- __read_lock_debug(lock);
+ __raw_read_lock(&lock->raw_lock);
}
int _raw_read_trylock(rwlock_t *lock)
@@ -235,6 +236,7 @@ static inline void debug_write_unlock(rwlock_t *lock)
lock->owner_cpu = -1;
}
+#if 0 /* This can cause lockups */
static void __write_lock_debug(rwlock_t *lock)
{
int print_once = 1;
@@ -257,12 +259,12 @@ static void __write_lock_debug(rwlock_t *lock)
}
}
}
+#endif
void _raw_write_lock(rwlock_t *lock)
{
debug_write_lock_before(lock);
- if (unlikely(!__raw_write_trylock(&lock->raw_lock)))
- __write_lock_debug(lock);
+ __raw_write_lock(&lock->raw_lock);
debug_write_lock_after(lock);
}