diff options
| author | Mike Galbraith <mgalbraith@suse.de> | 2012-11-28 07:17:18 +0100 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2012-12-01 15:56:42 -0800 |
| commit | 412d32e6c98527078779e5b515823b2810e40324 (patch) | |
| tree | 0221e047afeb05d753d29821a457eef9dbe917d7 | |
| parent | b3c3a9cf2a28ee4a8d0b62e2e58c61e9ca9bb47b (diff) | |
| download | lwn-412d32e6c98527078779e5b515823b2810e40324.tar.gz lwn-412d32e6c98527078779e5b515823b2810e40324.zip | |
workqueue: exit rescuer_thread() as TASK_RUNNING
A rescue thread exiting TASK_INTERRUPTIBLE can lead to a task scheduling
off, never to be seen again. In the case where this occurred, an exiting
thread hit reiserfs homebrew conditional resched while holding a mutex,
bringing the box to its knees.
PID: 18105 TASK: ffff8807fd412180 CPU: 5 COMMAND: "kdmflush"
#0 [ffff8808157e7670] schedule at ffffffff8143f489
#1 [ffff8808157e77b8] reiserfs_get_block at ffffffffa038ab2d [reiserfs]
#2 [ffff8808157e79a8] __block_write_begin at ffffffff8117fb14
#3 [ffff8808157e7a98] reiserfs_write_begin at ffffffffa0388695 [reiserfs]
#4 [ffff8808157e7ad8] generic_perform_write at ffffffff810ee9e2
#5 [ffff8808157e7b58] generic_file_buffered_write at ffffffff810eeb41
#6 [ffff8808157e7ba8] __generic_file_aio_write at ffffffff810f1a3a
#7 [ffff8808157e7c58] generic_file_aio_write at ffffffff810f1c88
#8 [ffff8808157e7cc8] do_sync_write at ffffffff8114f850
#9 [ffff8808157e7dd8] do_acct_process at ffffffff810a268f
[exception RIP: kernel_thread_helper]
RIP: ffffffff8144a5c0 RSP: ffff8808157e7f58 RFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8107af60 RDI: ffff8803ee491d18
RBP: 0000000000000000 R8: 0000000000000000 R9: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
| -rw-r--r-- | kernel/workqueue.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 042d221d33cc..ac25db111f48 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2407,8 +2407,10 @@ static int rescuer_thread(void *__wq) repeat: set_current_state(TASK_INTERRUPTIBLE); - if (kthread_should_stop()) + if (kthread_should_stop()) { + __set_current_state(TASK_RUNNING); return 0; + } /* * See whether any cpu is asking for help. Unbounded |