From: Daniel Walker <dwalker@fifo99.com>
To: fweisbec@gmail.com
Cc: msb@chromium.org, sshaiju@mvista.com, mingo@elte.hu,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org
Subject: hung_task checking and sys_sync
Date: Tue, 12 Jun 2012 15:09:24 -0700 [thread overview]
Message-ID: <20120612220924.GA13376@fifo99.com> (raw)
I found this commit which was a while ago,
commit fb822db465bd9fd4208eef1af4490539b236c54e
Author: Ingo Molnar <mingo@elte.hu>
Date: Wed Aug 20 11:17:40 2008 +0200
softlockup: increase hung tasks check from 2 minutes to 8 minutes
Andrew says:
> Seems that about 100% of the reports we get of this warning triggering
> are sys_sync, transaction commit, etc.
increase the timeout. If it still triggers for people, we can kill it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We're seeing these messages on an older kernel (montavista) but the code areas
appear similar to current kernels. The issue is that we're doing a file copy
which takes 10-15minutes, and in the background there is a "df --sync"
happening (which is calling sys_sync). We end up getting a hung task message
like below,
INFO: task df:1778 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
ffffffff81578d40 0000000000000086 ffff8801f6135b00 ffff880269a91800
ffff880269a91800 ffff8802702be000 ffff8801f602a080 0000000000000000
ffff8801f602a440 ffffffff8109c166 ffff8801e863de18 0000000000000004
Call Trace:
[<ffffffff8109c166>] ? sync_page+0x0/0x49
[<ffffffff81320de2>] ? __schedule+0x3c/0x57
[<ffffffff810ea3c7>] ? bdi_sched_wait+0x0/0xe
[<ffffffff81320de2>] ? __schedule+0x3c/0x57
[<ffffffff81320e0d>] ? schedule+0x10/0x1e
[<ffffffff810ea3d0>] ? bdi_sched_wait+0x9/0xe
There some variation in the stack trace , but always thru bdi_sched_wait().
These don't seem like valid warnings, since the copy happening is know to take
a long time. Has there been any commit that disable these messages bdi_sched_wait?
Daniel
next reply other threads:[~2012-06-12 22:09 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-12 22:09 Daniel Walker [this message]
2012-06-12 22:29 ` hung_task checking and sys_sync Mandeep Singh Baines
2012-06-12 22:34 ` Daniel Walker
2012-06-12 22:45 ` Mandeep Baines
2012-06-12 22:57 ` Daniel Walker
2012-06-13 1:03 ` Muthu Kumar
2012-06-13 15:43 ` Daniel Walker
2012-06-13 3:02 ` Sadasivan Shaiju
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