path: root/fs/fs-writeback.c
diff options
authorTejun Heo <tj@kernel.org>2013-04-30 15:27:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-04-30 17:04:02 -0700
commitef3b101925f2170c2b8cd2e126b37492ae02f77c (patch)
treeaca0ee1ca4866713c75c9b0ecb19598f41c22969 /fs/fs-writeback.c
parent3d1cb2059d9374e58da481b783332cf191cb6620 (diff)
writeback: set worker desc to identify writeback workers in task dumps
Writeback has been recently converted to use workqueue instead of its private thread pool implementation. One negative side effect of this conversion is that there's no easy to tell which backing device a writeback work item was working on at the time of task dump, be it sysrq-t, BUG, WARN or whatever, which, according to our writeback brethren, is important in tracking down issues with a lot of mounted file systems on a lot of different devices. This patch restores that information using the new worker description facility. bdi_writeback_workfn() calls set_work_desc() to identify which bdi it's working on. The description is printed out together with the worqueue name and worker function as in the following example dump. WARNING: at fs/fs-writeback.c:1015 bdi_writeback_workfn+0x2b4/0x3c0() Modules linked in: Pid: 28, comm: kworker/u18:0 Not tainted 3.9.0-rc1-work+ #24 empty empty/S3992 Workqueue: writeback bdi_writeback_workfn (flush-8:16) ffffffff820a3a98 ffff88015b927cb8 ffffffff81c61855 ffff88015b927cf8 ffffffff8108f500 0000000000000000 ffff88007a171948 ffff88007a1716b0 ffff88015b49df00 ffff88015b8d3940 0000000000000000 ffff88015b927d08 Call Trace: [<ffffffff81c61855>] dump_stack+0x19/0x1b [<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0 [<ffffffff8108f54a>] warn_slowpath_null+0x1a/0x20 [<ffffffff81200144>] bdi_writeback_workfn+0x2b4/0x3c0 [<ffffffff810b4c87>] process_one_work+0x1d7/0x660 [<ffffffff810b5c72>] worker_thread+0x122/0x380 [<ffffffff810bdfea>] kthread+0xea/0xf0 [<ffffffff81c6cedc>] ret_from_fork+0x7c/0xb0 Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/fs-writeback.c')
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 21f46fb3a10..798d4458a4d 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1028,6 +1028,7 @@ int bdi_writeback_thread(void *data)
struct backing_dev_info *bdi = wb->bdi;
long pages_written;
+ set_worker_desc("flush-%s", dev_name(bdi->dev));
current->flags |= PF_SWAPWRITE;
wb->last_active = jiffies;