lkml.org 
[lkml]   [2016]   [Aug]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] sched: Avoid that __wait_on_bit_lock() hangs
From
Date
On 08/09/2016 10:15 AM, Oleg Nesterov wrote:
> On 08/08, Bart Van Assche wrote:
>>
>> No external modules were loaded when I triggered the lockup
>
> Heh. Could you test the patch below?
>
> Oleg.
>
> --- x/kernel/sched/wait.c
> +++ x/kernel/sched/wait.c
> @@ -283,7 +283,7 @@ void abort_exclusive_wait(wait_queue_hea
> if (!list_empty(&wait->task_list))
> list_del_init(&wait->task_list);
> else if (waitqueue_active(q))
> - __wake_up_locked_key(q, mode, key);
> + __wake_up_locked_key(q, TASK_NORMAL, key);
> spin_unlock_irqrestore(&q->lock, flags);
> }
> EXPORT_SYMBOL(abort_exclusive_wait);

Hello Oleg,

That patch looks interesting to me. Unfortunately even with that patch
applied I still see lockups. These are the two lockups I have observed
after I had applied your patch, rebuilt and reinstalled the kernel and
rebooted the test server:

[ 1548.018115] sysrq: SysRq : Show Blocked State
[ 1548.018210] task PC stack pid father
[ 1548.018677] systemd-udevd D ffff8803a9f13be8 0 29908 483 0x00000000
[ 1548.018792] ffff8803a9f13be8 ffffffff82584bd0 00ffffff8252b1b0 ffff88046f0569c0
[ 1548.018961] ffff88016c98b140 ffff8800757bc9c0 ffff8803a9f14000 ffff88046f0569c0
[ 1548.019131] 7fffffffffffffff ffffffff8161fcf0 ffff8803a9f13d50 ffff8803a9f13c00
[ 1548.019316] Call Trace:
[ 1548.019415] [<ffffffff8161f567>] schedule+0x37/0x90
[ 1548.019464] [<ffffffff81623bbf>] schedule_timeout+0x27f/0x470
[ 1548.019758] [<ffffffff8161e93f>] io_schedule_timeout+0x9f/0x110
[ 1548.019808] [<ffffffff8161fd06>] bit_wait_io+0x16/0x60
[ 1548.019856] [<ffffffff8161f996>] __wait_on_bit+0x56/0x80
[ 1548.019906] [<ffffffff81152e1d>] wait_on_page_bit_killable+0xbd/0xc0
[ 1548.020006] [<ffffffff81152f50>] generic_file_read_iter+0x130/0x770
[ 1548.020158] [<ffffffff812134a0>] blkdev_read_iter+0x30/0x40
[ 1548.020209] [<ffffffff811d266b>] __vfs_read+0xbb/0x130
[ 1548.020258] [<ffffffff811d2a51>] vfs_read+0x91/0x130
[ 1548.020305] [<ffffffff811d3dd4>] SyS_read+0x44/0xa0
[ 1548.020354] [<ffffffff81624fa5>] entry_SYSCALL_64_fastpath+0x18/0xa8

[ 1050.892823] sysrq: SysRq : Show Blocked State
[ 1050.892912] task PC stack pid father
[ 1050.893333] systemd-udevd D ffff880449b3f838 0 17240 492 0x00000006
[ 1050.893974] Call Trace:
[ 1050.894119] [<ffffffff8161f567>] schedule+0x37/0x90
[ 1050.894168] [<ffffffff81623bcf>] schedule_timeout+0x27f/0x470
[ 1050.894561] [<ffffffff8161e93f>] io_schedule_timeout+0x9f/0x110
[ 1050.894609] [<ffffffff8161fd16>] bit_wait_io+0x16/0x60
[ 1050.894657] [<ffffffff8161fb09>] __wait_on_bit_lock+0x49/0xa0
[ 1050.894705] [<ffffffff8114fe59>] __lock_page+0xb9/0xc0
[ 1050.894802] [<ffffffff81165d80>] truncate_inode_pages_range+0x3e0/0x760
[ 1050.895750] [<ffffffff81166110>] truncate_inode_pages+0x10/0x20
[ 1050.895799] [<ffffffff81212a10>] kill_bdev+0x30/0x40
[ 1050.895849] [<ffffffff81213d31>] __blkdev_put+0x71/0x360
[ 1050.895951] [<ffffffff81214069>] blkdev_put+0x49/0x170
[ 1050.895998] [<ffffffff812141b0>] blkdev_close+0x20/0x30
[ 1050.896047] [<ffffffff811d48d8>] __fput+0xe8/0x1f0
[ 1050.896094] [<ffffffff811d4a19>] ____fput+0x9/0x10
[ 1050.896141] [<ffffffff810842d3>] task_work_run+0x83/0xb0
[ 1050.896189] [<ffffffff8106606e>] do_exit+0x3ee/0xc40
[ 1050.896284] [<ffffffff8106694b>] do_group_exit+0x4b/0xc0
[ 1050.896331] [<ffffffff81073d9a>] get_signal+0x2ca/0x940
[ 1050.896425] [<ffffffff8101bf43>] do_signal+0x23/0x660
[ 1050.896626] [<ffffffff810022b3>] exit_to_usermode_loop+0x73/0xb0
[ 1050.896678] [<ffffffff81002cb0>] syscall_return_slowpath+0xb0/0xc0
[ 1050.896727] [<ffffffff81625033>] entry_SYSCALL_64_fastpath+0xa6/0xa8

Bart.

\
 
 \ /
  Last update: 2016-08-09 21:21    [W:0.090 / U:1.916 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site