From: Zheng Liu <gnehzuil.liu@gmail.com>
To: Sandeep Joshi <sanjos100@gmail.com>
Cc: Jan Kara <jack@suse.cz>, linux-ext4@vger.kernel.org
Subject: Re: process hangs in ext4_sync_file
Date: Thu, 24 Oct 2013 11:54:36 +0800 [thread overview]
Message-ID: <20131024035435.GA27467@gmail.com> (raw)
In-Reply-To: <CAEfL3KnUhETAWeh-OoRYTR5GxYL26TjaT=j_WDZeW5xa3vAdeg@mail.gmail.com>
On Wed, Oct 23, 2013 at 08:28:22PM +0530, Sandeep Joshi wrote:
> On Wed, Oct 23, 2013 at 3:50 PM, Jan Kara <jack@suse.cz> wrote:
> > 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
>
>
> Thanks Jan, I will remove it and see what happens.
> I was also planning to switch to ext2 and see if the failure continues.
> I added the discard option because the filesystem was initially
> supposed to be on an SSD
>
> is there any document which tells me what to look for in the output of
> "echo w > /proc/sysrq-trigger" ?
Sorry for the late. Here it is [1]. I want to look at which process is
blocked. Please try the testing as Jan suggested.
1. http://lxr.free-electrons.com/source/Documentation/sysrq.txt
Regards,
- Zheng
next prev parent reply other threads:[~2013-10-24 3:52 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
2013-10-23 14:58 ` Sandeep Joshi
2013-10-24 3:54 ` Zheng Liu [this message]
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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