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| author | Mark Lord <kernel@teksavvy.com> | 2010-09-24 09:51:13 -0400 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2010-09-24 15:52:09 +0200 |
| commit | 4b1977698ceb4c4caa800d475127139da49966f9 (patch) | |
| tree | 9302bafc15dfb6d3923febaa982feb2cb12063cb /block/blk-exec.c | |
| parent | 749ef9f8423054e326f3a246327ed2db4b6d395f (diff) | |
| download | lwn-4b1977698ceb4c4caa800d475127139da49966f9.tar.gz lwn-4b1977698ceb4c4caa800d475127139da49966f9.zip | |
block: Prevent hang_check firing during long I/O
During long I/O operations, the hang_check timer may fire,
trigger stack dumps that unnecessarily alarm the user.
Eg. hdparm --security-erase NULL /dev/sdb ## can take *hours* to complete
So, if hang_check is armed, we should wake up periodically
to prevent it from triggering. This patch uses a wake-up interval
equal to half the hang_check timer period, which keeps overhead low enough.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'block/blk-exec.c')
| -rw-r--r-- | block/blk-exec.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/block/blk-exec.c b/block/blk-exec.c index e1672f14840e..cf1456a02acd 100644 --- a/block/blk-exec.c +++ b/block/blk-exec.c @@ -80,6 +80,7 @@ int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk, DECLARE_COMPLETION_ONSTACK(wait); char sense[SCSI_SENSE_BUFFERSIZE]; int err = 0; + unsigned long hang_check; /* * we need an extra reference to the request, so we can look at @@ -95,7 +96,13 @@ int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk, rq->end_io_data = &wait; blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq); - wait_for_completion(&wait); + + /* Prevent hang_check timer from firing at us during very long I/O */ + hang_check = sysctl_hung_task_timeout_secs; + if (hang_check) + while (!wait_for_completion_timeout(&wait, hang_check * (HZ/2))); + else + wait_for_completion(&wait); if (rq->errors) err = -EIO; |