From: Michal Hocko <mhocko@kernel.org>
To: Tejun Heo <tj@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: WARNING: CPU: 3 PID: 1568 at kernel/sched/core.c:7738 __might_sleep+0x69/0x7e
Date: Fri, 9 Dec 2016 16:12:29 +0100 [thread overview]
Message-ID: <20161209151229.GD4334@dhcp22.suse.cz> (raw)
Hi Tejun,
I am seeing the following warning during boot in my kvm testing
environment:
[ 3.549649] WARNING: CPU: 3 PID: 1568 at kernel/sched/core.c:7738 __might_sleep+0x69/0x7e
[ 3.551279] do not call blocking ops when !TASK_RUNNING; state=2 set at [<ffffffff81098621>] prepare_to_wait+0x65/0xac
[ 3.553354] Modules linked in:
[ 3.554032] CPU: 3 PID: 1568 Comm: modprobe Not tainted 4.9.0-rc8-nofstest5-next-20161209-00013-g3134766e941a #1018
[ 3.556099] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014
[ 3.557330] Call Trace:
[ 3.557330] dump_stack+0x68/0x92
[ 3.557330] __warn+0xc2/0xdd
[ 3.557330] warn_slowpath_fmt+0x4b/0x53
[ 3.557330] ? prepare_to_wait+0x65/0xac
[ 3.557330] ? prepare_to_wait+0x65/0xac
[ 3.557330] __might_sleep+0x69/0x7e
[ 3.557330] do_ide_request+0x47/0x540
[ 3.557330] ? __lock_is_held+0x47/0x7a
[ 3.557330] ? hrtimer_try_to_cancel+0x15f/0x1c6
[ 3.557330] ? _raw_spin_unlock_irqrestore+0x4c/0x61
[ 3.557330] __blk_run_queue+0x31/0x3a
[ 3.557330] cfq_insert_request+0x331/0x429
[ 3.557330] __elv_add_request+0x2bb/0x346
[ 3.557330] blk_flush_plug_list+0x1da/0x21f
[ 3.557330] ? bit_wait+0x50/0x50
[ 3.557330] io_schedule_timeout+0x47/0x102
[ 3.557330] bit_wait_io+0x1b/0x5a
[ 3.557330] __wait_on_bit+0x4d/0x7b
[ 3.557330] out_of_line_wait_on_bit+0x72/0x7d
[ 3.557330] ? bit_wait+0x50/0x50
[ 3.557330] ? autoremove_wake_function+0x4e/0x4e
[ 3.557330] __wait_on_buffer+0x40/0x43
[ 3.557330] bh_submit_read+0x60/0x72
[ 3.557330] ext4_get_branch+0x91/0x115
[ 3.557330] ext4_ind_map_blocks+0x181/0xa16
[ 3.557330] ? __lock_is_held+0x47/0x7a
[ 3.557330] ? lock_acquire+0x133/0x1c7
[ 3.557330] ext4_map_blocks+0x120/0x4ca
[ 3.557330] ext4_mpage_readpages+0x2a7/0x70a
[ 3.557330] ext4_readpages+0x33/0x35
[ 3.557330] __do_page_cache_readahead+0x239/0x32a
[ 3.557330] filemap_fault+0x180/0x602
[ 3.557330] ? filemap_fault+0x180/0x602
[ 3.557330] ext4_filemap_fault+0x37/0x4b
[ 3.557330] __do_fault+0x1f/0x94
[ 3.557330] handle_mm_fault+0x946/0xfca
[ 3.557330] __do_page_fault+0x361/0x518
[ 3.557330] do_page_fault+0x42/0x5f
[ 3.557330] page_fault+0x22/0x30
At first I thought this would be related to you recent work
http://lkml.kernel.org/r/1477673892-28940-1-git-send-email-tj@kernel.org
but that doesn't seem to be in the linux-next I am using as a base.
io_schedule_timeout is on the stack though so you might have an idea
what is going on here. That might_sleep check has been added a long ago
02e7cf8f8488 ("ide-cd,atapi: use bio for internal commands") in 2.6.31
so I am wondering what has changed since than.
Thanks!
--
Michal Hocko
SUSE Labs
next reply other threads:[~2016-12-09 15:12 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-09 15:12 Michal Hocko [this message]
2016-12-12 22:03 ` WARNING: CPU: 3 PID: 1568 at kernel/sched/core.c:7738 __might_sleep+0x69/0x7e Tejun Heo
2016-12-12 22:30 ` Cong Wang
2016-12-12 22:45 ` Shaohua Li
2016-12-21 10:47 ` Michal Hocko
2016-12-21 19:24 ` Cong Wang
2016-12-21 20:57 ` Michal Hocko
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