From: Jan Kara <jack@suse.cz>
To: Sandeep Joshi <sanjos100@gmail.com>
Cc: linux-ext4@vger.kernel.org
Subject: Re: process hangs in ext4_sync_file
Date: Wed, 23 Oct 2013 12:20:42 +0200 [thread overview]
Message-ID: <20131023102042.GE1275@quack.suse.cz> (raw)
In-Reply-To: <CAEfL3KniKZNzehPH1Z4eWhhNF_RHrE4vHoRTHDPrfYj4t_2LtA@mail.gmail.com>
On Mon 21-10-13 18:09:02, Sandeep Joshi wrote:
> I am seeing a problem reported 4 years earlier
> https://lkml.org/lkml/2009/3/12/226
> (same stack as seen by Alexander)
>
> The problem is reproducible. Let me know if you need any info in
> addition to that seen below.
>
> I have multiple threads in a process doing heavy IO on a ext4
> filesystem mounted with (discard, noatime) on a SSD or HDD.
>
> This is on Linux 3.8.0-29-generic #42~precise1-Ubuntu SMP Wed Aug 14
> 16:19:23 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
>
> For upto minutes at a time, one of the threads seems to hang in sync to disk.
>
> When I check the thread stack in /proc, I find that the stack is one
> of the following two
>
> <ffffffff81134a4e>] sleep_on_page+0xe/0x20
> [<ffffffff81134c88>] wait_on_page_bit+0x78/0x80
> [<ffffffff81134d9c>] filemap_fdatawait_range+0x10c/0x1a0
> [<ffffffff811367d8>] filemap_write_and_wait_range+0x68/0x80
> [<ffffffff81236a4f>] ext4_sync_file+0x6f/0x2b0
> [<ffffffff811cba9b>] vfs_fsync+0x2b/0x40
> [<ffffffff81168fb3>] sys_msync+0x143/0x1d0
> [<ffffffff816fc8dd>] system_call_fastpath+0x1a/0x1f
> [<ffffffffffffffff>] 0xffffffffffffffff
>
>
> OR
>
>
> [<ffffffff812947f5>] jbd2_log_wait_commit+0xb5/0x130
> [<ffffffff81297213>] jbd2_complete_transaction+0x53/0x90
> [<ffffffff81236bcd>] ext4_sync_file+0x1ed/0x2b0
> [<ffffffff811cba9b>] vfs_fsync+0x2b/0x40
> [<ffffffff81168fb3>] sys_msync+0x143/0x1d0
> [<ffffffff816fc8dd>] system_call_fastpath+0x1a/0x1f
> [<ffffffffffffffff>] 0xffffffffffffffff
>
> Any clues?
We are waiting for IO to complete. As the first thing, try to remount
your filesystem without 'discard' mount option. That is often causing
problems.
Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR
next prev parent reply other threads:[~2013-10-23 10:20 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-21 12:39 process hangs in ext4_sync_file Sandeep Joshi
2013-10-21 12:57 ` Zheng Liu
2013-10-22 3:24 ` Sandeep Joshi
2013-10-22 8:45 ` Sandeep Joshi
2013-10-23 10:20 ` Jan Kara [this message]
2013-10-23 14:58 ` Sandeep Joshi
2013-10-24 3:54 ` Zheng Liu
2013-10-29 5:36 ` Sandeep Joshi
[not found] ` <CAEfL3KmAXw+mE24kZkG4YHU3C98rU6pkbAwMhSO1pw1rg81HVw@mail.gmail.com>
2013-10-29 14:46 ` Jan Kara
2013-10-29 15:00 ` Sandeep Joshi
2013-10-29 15:26 ` Jan Kara
2013-10-29 17:04 ` Christoph Hellwig
2013-10-29 17:53 ` Jan Kara
2014-01-06 10:28 ` Sandeep Joshi
2014-01-06 14:32 ` Theodore Ts'o
2014-01-06 15:08 ` Sandeep Joshi
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