From: Gleb Natapov <gleb@redhat.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: automount hangs during boot somewhere in rcu_barrier.
Date: Mon, 4 Jun 2012 10:48:03 +0300 [thread overview]
Message-ID: <20120604074803.GA23670@redhat.com> (raw)
In-Reply-To: <20120604031549.GE2357@linux.vnet.ibm.com>
On Sun, Jun 03, 2012 at 08:15:49PM -0700, Paul E. McKenney wrote:
> On Sun, Jun 03, 2012 at 02:32:36PM +0300, Gleb Natapov wrote:
> > Hello Paul,
> >
> > I see something strange with 3.5.0-rc1 kernel. During boot automount
> > process hangs for a couple of minutes and when boot finally completes
> > I find this in dmesg:
> >
> > [ 240.676287] INFO: task automount:3000 blocked for more than 120 seconds.
> > [ 240.676393] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> > [ 240.676495] automount D ffff88027fc12040 0 3000 2994 0x00000000
> > [ 240.676581] ffff880273e7dcb8 0000000000000046 ffff880273e7dc70 ffff880273e7dfd8
> > [ 240.676681] 0000000000004000 0000000000012040 ffffffff814e3410 ffff8802732a4100
> > [ 240.676781] ffff880272470a20 ffff8802732f5001 0000000000000009 ffff880273e7de18
> > [ 240.676880] Call Trace:
> > [ 240.676962] [<ffffffff81186bae>] ? security_inode_permission+0x1e/0x20
> > [ 240.677072] [<ffffffff8114ad90>] ? fsnotify_clear_marks_by_inode+0x93/0xd4
> > [ 240.677169] [<ffffffff8105ae20>] ? sub_preempt_count+0x38/0x4b
> > [ 240.677260] [<ffffffff8137e738>] schedule+0x64/0x66
> > [ 240.677348] [<ffffffff8137cad4>] schedule_timeout+0x2b/0x28b
> > [ 240.677435] [<ffffffff8137dcdd>] ? wait_for_common+0xc0/0x146
> > [ 240.677523] [<ffffffff8105ae20>] ? sub_preempt_count+0x38/0x4b
> > [ 240.677610] [<ffffffff8137dce5>] wait_for_common+0xc8/0x146
> > [ 240.677699] [<ffffffff8109a1cd>] ? synchronize_sched_expedited_cpu_stop+0x10/0x10
> > [ 240.677804] [<ffffffff8105c963>] ? try_to_wake_up+0x24f/0x24f
> > [ 240.677892] [<ffffffff8137dd80>] wait_for_completion+0x1d/0x1f
> > [ 240.677979] [<ffffffff8109a6b4>] _rcu_barrier+0x204/0x21f
> > [ 240.678085] [<ffffffff8109c560>] ? kfree_call_rcu+0x1c/0x1c
> > [ 240.678178] [<ffffffff8109a48b>] ? rcu_implicit_dynticks_qs+0x191/0x191
> > [ 240.678272] [<ffffffff8109a6eb>] rcu_barrier+0x1c/0x1e
> > [ 240.678359] [<ffffffff81119060>] deactivate_locked_super+0x37/0x57
> > [ 240.678447] [<ffffffff81119cae>] deactivate_super+0x3f/0x43
> > [ 240.678535] [<ffffffff8112fdd9>] mntput_no_expire+0x132/0x13a
> > [ 240.678622] [<ffffffff81130c15>] sys_umount+0x308/0x33a
> > [ 240.678708] [<ffffffff81380092>] system_call_fastpath+0x16/0x1b
> >
> > When I am actually trying to access automounted NFS directory nfs mount
> > also hangs in D state in rcu_barrier (I see this behaviour in 3.4 and it
> > looks like 3.3 kernel too).
>
> So this did not happen in 3.2?
>
Do not remember. Need to check.
> > My kernel config is attached.
>
> Hmmm... Could you please try disabling CONFIG_RCU_FAST_NO_HZ? If that
> makes the problem go away, I have some patches 3.6-targeted patches
> for you.
Will report back.
--
Gleb.
next prev parent reply other threads:[~2012-06-04 7:48 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-03 11:32 automount hangs during boot somewhere in rcu_barrier Gleb Natapov
2012-06-04 3:15 ` Paul E. McKenney
2012-06-04 7:48 ` Gleb Natapov [this message]
2012-06-04 10:09 ` Gleb Natapov
2012-06-04 14:54 ` Paul E. McKenney
2012-06-05 9:46 ` Gleb Natapov
2012-06-05 15:19 ` Paul E. McKenney
2012-06-05 18:27 ` Gleb Natapov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20120604074803.GA23670@redhat.com \
--to=gleb@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=paulmck@linux.vnet.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.