diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2006-11-05 23:52:10 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-11-06 01:46:23 -0800 |
| commit | 64efade11cddc4237c1b95ea4ca18af122a7e19e (patch) | |
| tree | 0a98f64b43f1b1199a45bcdff07743afbb526989 | |
| parent | e5b9a335fd2180c6db1bcc4b24e83aff7481ebe3 (diff) | |
[PATCH] lockdep: fix delayacct locking bug
Make the delayacct lock irqsave; this avoids the possible deadlock where
an interrupt is taken while holding the delayacct lock which needs to
take the delayacct lock.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | kernel/delayacct.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 36752f124c6..66a0ea48751 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -66,6 +66,7 @@ static void delayacct_end(struct timespec *start, struct timespec *end, { struct timespec ts; s64 ns; + unsigned long flags; do_posix_clock_monotonic_gettime(end); ts = timespec_sub(*end, *start); @@ -73,10 +74,10 @@ static void delayacct_end(struct timespec *start, struct timespec *end, if (ns < 0) return; - spin_lock(¤t->delays->lock); + spin_lock_irqsave(¤t->delays->lock, flags); *total += ns; (*count)++; - spin_unlock(¤t->delays->lock); + spin_unlock_irqrestore(¤t->delays->lock, flags); } void __delayacct_blkio_start(void) @@ -104,6 +105,7 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) s64 tmp; struct timespec ts; unsigned long t1,t2,t3; + unsigned long flags; /* Though tsk->delays accessed later, early exit avoids * unnecessary returning of other data @@ -136,14 +138,14 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) /* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */ - spin_lock(&tsk->delays->lock); + spin_lock_irqsave(&tsk->delays->lock, flags); tmp = d->blkio_delay_total + tsk->delays->blkio_delay; d->blkio_delay_total = (tmp < d->blkio_delay_total) ? 0 : tmp; tmp = d->swapin_delay_total + tsk->delays->swapin_delay; d->swapin_delay_total = (tmp < d->swapin_delay_total) ? 0 : tmp; d->blkio_count += tsk->delays->blkio_count; d->swapin_count += tsk->delays->swapin_count; - spin_unlock(&tsk->delays->lock); + spin_unlock_irqrestore(&tsk->delays->lock, flags); done: return 0; @@ -152,11 +154,12 @@ done: __u64 __delayacct_blkio_ticks(struct task_struct *tsk) { __u64 ret; + unsigned long flags; - spin_lock(&tsk->delays->lock); + spin_lock_irqsave(&tsk->delays->lock, flags); ret = nsec_to_clock_t(tsk->delays->blkio_delay + tsk->delays->swapin_delay); - spin_unlock(&tsk->delays->lock); + spin_unlock_irqrestore(&tsk->delays->lock, flags); return ret; } |