From: Dave Chinner <david@fromorbit.com>
To: linux-kernel@vger.kernel.org
Subject: [lockdep, sysfs]: lockdep compliant when chaging io schedulers
Date: Mon, 11 Jan 2010 18:54:16 +1100 [thread overview]
Message-ID: <20100111075416.GF4019@discord.disaster> (raw)
This output occurred on 2.6.33-rc3 when changing the schedler from cfq to noop.
[ 129.838942] =============================================
[ 129.839006] [ INFO: possible recursive locking detected ]
[ 129.839006] 2.6.33-rc3-dgc #14
[ 129.839006] ---------------------------------------------
[ 129.839006] sh/3921 is trying to acquire lock:
[ 129.839006] (s_active){++++.+}, at: [<ffffffff8117fa7e>] sysfs_remove_dir+0x7e/0xa0
[ 129.839006]
[ 129.839006] but task is already holding lock:
[ 129.839006] (s_active){++++.+}, at: [<ffffffff8117f4fd>] sysfs_get_active_two+0x3d/0x60
[ 129.839006]
[ 129.839006] other info that might help us debug this:
[ 129.839006] 4 locks held by sh/3921:
[ 129.839006] #0: (&buffer->mutex){+.+.+.}, at: [<ffffffff8117e0b9>] sysfs_write_file+0x49/0x150
[ 129.839006] #1: (s_active){++++.+}, at: [<ffffffff8117f4fd>] sysfs_get_active_two+0x3d/0x60
[ 129.839006] #2: (s_active){++++.+}, at: [<ffffffff8117f4e7>] sysfs_get_active_two+0x27/0x60
[ 129.839006] #3: (&q->sysfs_lock){+.+.+.}, at: [<ffffffff813cb1e4>] queue_attr_store+0x54/0xb0
[ 129.839006]
[ 129.839006] stack backtrace:
[ 129.839006] Pid: 3921, comm: sh Not tainted 2.6.33-rc3-dgc #14
[ 129.839006] Call Trace:
[ 129.839006] [<ffffffff81084563>] __lock_acquire+0x1503/0x17a0
[ 129.839006] [<ffffffff81082ea2>] ? debug_check_no_locks_freed+0xa2/0x160
[ 129.839006] [<ffffffff81082795>] ? trace_hardirqs_on_caller+0x135/0x180
[ 129.839006] [<ffffffff810848ce>] lock_acquire+0xce/0x100
[ 129.839006] [<ffffffff8117fa7e>] ? sysfs_remove_dir+0x7e/0xa0
[ 129.839006] [<ffffffff8117f90c>] sysfs_addrm_finish+0xec/0x180
[ 129.839006] [<ffffffff8117fa7e>] ? sysfs_remove_dir+0x7e/0xa0
[ 129.839006] [<ffffffff810824c3>] ? mark_held_locks+0x73/0x90
[ 129.839006] [<ffffffff81073180>] ? cpu_clock+0x50/0x60
[ 129.839006] [<ffffffff8117fa7e>] sysfs_remove_dir+0x7e/0xa0
[ 129.839006] [<ffffffff813dd606>] kobject_del+0x16/0x40
[ 129.839006] [<ffffffff813c2246>] elv_iosched_store+0xf6/0x260
[ 129.839006] [<ffffffff813cb1fa>] queue_attr_store+0x6a/0xb0
[ 129.839006] [<ffffffff8117e149>] sysfs_write_file+0xd9/0x150
[ 129.839006] [<ffffffff8111c072>] vfs_write+0xb2/0xf0
[ 129.839006] [<ffffffff8111c1a5>] sys_write+0x55/0x90
[ 129.839006] [<ffffffff81002fdb>] system_call_fastpath+0x16/0x1b
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
reply other threads:[~2010-01-11 7:54 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=20100111075416.GF4019@discord.disaster \
--to=david@fromorbit.com \
--cc=linux-kernel@vger.kernel.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).