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| author | Oleg Nesterov <oleg@tv-sign.ru> | 2007-05-09 02:34:08 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-09 12:30:52 -0700 |
| commit | 36aa9dfc39bf473780439f5629c30f59d677e793 (patch) | |
| tree | 301d615747210733a271c376fc036a7480594207 /kernel/workqueue.c | |
| parent | d721304dce0ced0b3b0366996cc02929669708a8 (diff) | |
| download | blackbird-op-linux-36aa9dfc39bf473780439f5629c30f59d677e793.tar.gz blackbird-op-linux-36aa9dfc39bf473780439f5629c30f59d677e793.zip | |
workqueue: don't clear cwq->thread until it exits
Pointed out by Srivatsa Vaddagiri.
cleanup_workqueue_thread() sets cwq->thread = NULL and does kthread_stop().
This breaks the "if (cwq->thread == current)" logic in flush_cpu_workqueue()
and leads to deadlock.
Kill the thead first, then clear cwq->thread. workqueue_mutex protects us
from create_workqueue_thread() so we don't need cwq->lock.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>
Cc: Gautham shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/workqueue.c')
| -rw-r--r-- | kernel/workqueue.c | 15 |
1 files changed, 5 insertions, 10 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 1d1933cf3778..398c34ff6a54 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -625,17 +625,12 @@ EXPORT_SYMBOL_GPL(__create_workqueue); static void cleanup_workqueue_thread(struct workqueue_struct *wq, int cpu) { - struct cpu_workqueue_struct *cwq; - unsigned long flags; - struct task_struct *p; + struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); - cwq = per_cpu_ptr(wq->cpu_wq, cpu); - spin_lock_irqsave(&cwq->lock, flags); - p = cwq->thread; - cwq->thread = NULL; - spin_unlock_irqrestore(&cwq->lock, flags); - if (p) - kthread_stop(p); + if (cwq->thread) { + kthread_stop(cwq->thread); + cwq->thread = NULL; + } } /** |
