2008-06-03 20:06:57

by Alexey Dobriyan

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Subject: ftest01:16876 blocked for more than 120 seconds

This happened during LTP run together with mass-compiling kernels.
Kernel is 2.6.26-rc4-1beee8dc8cf58e3f605bd7b34d7a39939be7d8d2
fs is ext3 mounted with noatime.


INFO: task ftest01:16876 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
ftest01 D 0000000000000000 0 16876 16863
ffff810066fd3d68 0000000000000046 ffff810066fd3d08 ffffffff80254aae
ffff81005e7ab3c0 ffff810075530000 ffff81005e7ab600 0000000000000002
ffff810066fd3d28 ffffffff80254c55 ffff81000c043440 0000000000000282
Call Trace:
[<ffffffff80254aae>] ? mark_held_locks+0x3e/0x80
[<ffffffff80254c55>] ? trace_hardirqs_on+0xd5/0x160
[<ffffffff80460722>] ? _spin_unlock_irqrestore+0x42/0x80
[<ffffffff802a54a9>] inode_wait+0x9/0x10
[<ffffffff8045dfd5>] __wait_on_bit+0x55/0x80
[<ffffffff802a54a0>] ? inode_wait+0x0/0x10
[<ffffffff802b164a>] __writeback_single_inode+0x21a/0x320
[<ffffffff80247860>] ? wake_bit_function+0x0/0x30
[<ffffffff802b1bff>] sync_sb_inodes+0x1df/0x2d0
[<ffffffff802b1d8f>] sync_inodes_sb+0x9f/0xc0
[<ffffffff802b1e3a>] __sync_inodes+0x8a/0xe0
[<ffffffff802b1ebe>] sync_inodes+0x2e/0x40
[<ffffffff802b4f54>] do_sync+0x34/0x70
[<ffffffff802b4f9e>] sys_sync+0xe/0x20
[<ffffffff8020b68b>] system_call_after_swapgs+0x7b/0x80

1 lock held by ftest01/16876:
#0: (&type->s_umount_key#3){----}, at: [<ffffffff802b1e28>] __sync_inodes+0x78/0xe0



2008-06-04 16:56:25

by Jan Kara

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Subject: Re: ftest01:16876 blocked for more than 120 seconds

Hi,

> This happened during LTP run together with mass-compiling kernels.
> Kernel is 2.6.26-rc4-1beee8dc8cf58e3f605bd7b34d7a39939be7d8d2
> fs is ext3 mounted with noatime.
Thanks for report.

> INFO: task ftest01:16876 blocked for more than 120 seconds.
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> ftest01 D 0000000000000000 0 16876 16863
> ffff810066fd3d68 0000000000000046 ffff810066fd3d08 ffffffff80254aae
> ffff81005e7ab3c0 ffff810075530000 ffff81005e7ab600 0000000000000002
> ffff810066fd3d28 ffffffff80254c55 ffff81000c043440 0000000000000282
> Call Trace:
> [<ffffffff80254aae>] ? mark_held_locks+0x3e/0x80
> [<ffffffff80254c55>] ? trace_hardirqs_on+0xd5/0x160
> [<ffffffff80460722>] ? _spin_unlock_irqrestore+0x42/0x80
> [<ffffffff802a54a9>] inode_wait+0x9/0x10
> [<ffffffff8045dfd5>] __wait_on_bit+0x55/0x80
> [<ffffffff802a54a0>] ? inode_wait+0x0/0x10
> [<ffffffff802b164a>] __writeback_single_inode+0x21a/0x320
> [<ffffffff80247860>] ? wake_bit_function+0x0/0x30
> [<ffffffff802b1bff>] sync_sb_inodes+0x1df/0x2d0
> [<ffffffff802b1d8f>] sync_inodes_sb+0x9f/0xc0
> [<ffffffff802b1e3a>] __sync_inodes+0x8a/0xe0
> [<ffffffff802b1ebe>] sync_inodes+0x2e/0x40
> [<ffffffff802b4f54>] do_sync+0x34/0x70
> [<ffffffff802b4f9e>] sys_sync+0xe/0x20
> [<ffffffff8020b68b>] system_call_after_swapgs+0x7b/0x80
>
> 1 lock held by ftest01/16876:
> #0: (&type->s_umount_key#3){----}, at: [<ffffffff802b1e28>] __sync_inodes+0x78/0xe0
We are waiting for __I_SYNC - i.e., some other process is syncing
the inode and it took it longer than 120 sec to write this inode which
is well possible on heavily loaded system. I'm not sure we can do much here...

Honza
--
Jan Kara <[email protected]>
SuSE CR Labs