Date: Wed, 15 May 2013 07:15:01 +0000 (GMT)
From: EUNBONG SONG <eunb.song@samsung.com>
Subject: Question about ext4 excessive stall time
To: "linux-ext4@vger.kernel.org" <linux-ext4@vger.kernel.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "tytso@mit.edu" <tytso@mit.edu>, jack@suse.cz, dmonakhov@openvz.org,
        gnehzuil.liu@gmail.com
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Hello. 
I saw some commit messages about excessive stall times in ext4. 
The same problem was reproduced in my board. Actually, i'm not sure that is the same problem.
But the calltrace message is very similar with commit id: f783f091. 

My board configuration as follow.
Linux: 2.6.32.60
CPU: 8CPU
Disk: SSD
File system: ext4

I know my kernel version is so old. I just want to know why this problem is happened.
Because of my kernel version is old? or Because of disk ?,,
If anyone knows about this problem, Could you help me?

As i said,  the calltrace message is very similar with commit id: f783f091 as below.
Because i enabled hungtask detection and set the hungtask timeout to 120 seconds. 
the calltrace messages were printed by this. 

[  262.455615] INFO: task swm:1692 blocked for more than 120 seconds.
[  262.461715] Stack : 0000000000000000 ffffffff8011f684 0000000000000000 a8000001f8b33960
[  262.469438]         a8000001f7f2ce38 00000000ffffb6a9 0000000000000005 ffffffff80efa270
[  262.477424]         a8000001f7f2d0e8 0000000000000020 0000000000000000 ffffffff80ec69a0
[  262.485732]         00000001f90a3a50 a800000107c93020 a8000001f9062eb8 a8000001f9302950
[  262.493708]         a8000001f5121280 a8000001f90a3810 a8000001f7e20000 0000000000000000
[  262.501675]         0000000000000004 a800000107c93020 a8000001f8b339c0 ffffffff8011cd50
[  262.509661]         a8000001f9062eb8 ffffffff8011f684 0000000000000001 ffffffff8011cea8
[  262.517647]         a8000001f9302950 ffffffff804295a0 a8000001f9302950 0000001800000000
[  262.525652]         0000000000000000 a8000001f7f2ce38 ffffffff802e3f00 a8000001f4f73bb8
[  262.533631]         a800000107c93038 ffffffff8043987c 0000000000000000 a8000001f9302950
[  262.541603]         ...
[  262.544208] Call Trace:
[  262.546668] [<ffffffff8011c598>] __schedule_nobkl+0x278/0x900
[  262.552391] [<ffffffff8011cd50>] __schedule+0x48/0x80
[  262.557431] [<ffffffff8011cea8>] schedule+0x10/0x28
[  262.562269] [<ffffffff804295a0>] do_get_write_access+0x470/0x6a8
[  262.568285] [<ffffffff80434620>] jbd2_journal_get_write_access+0x30/0x58
[  262.574939] [<ffffffff804171a8>] __ext4_journal_get_write_access+0x48/0x88
[  262.581817] [<ffffffff803fc0f8>] ext4_reserve_inode_write+0x80/0xa8
[  262.588056] [<ffffffff803fc174>] ext4_mark_inode_dirty+0x54/0x1e8
[  262.594121] [<ffffffff803fc4a0>] ext4_dirty_inode+0x38/0x70
[  262.599745] [<ffffffff80381a98>] __mark_inode_dirty+0x40/0x228
[  262.605493] [<ffffffff803747bc>] file_update_time+0xec/0x190
[  262.611159] [<ffffffff8031cb20>] __generic_file_aio_write+0x1f8/0x3e8
[  262.617568] [<ffffffff8031cd70>] generic_file_aio_write+0x60/0xc0
[  262.623636] [<ffffffff8035c1f4>] do_sync_write+0xbc/0x120
[  262.629037] [<ffffffff8035ce24>] vfs_write+0xb4/0x178
[  262.634049] [<ffffffff8035cfd0>] SyS_write+0x48/0xa0
[  262.639022] [<ffffffff80102fc4>] handle_sys64+0x44/0x60
[  262.644221] 
262.645734] INFO: task evm:1814 blocked for more than 120 seconds.
[  262.651855] Stack : 0000000000000000 a8000001f442b930 0000000000000000 0000000000100100
[  262.659651]         a8000001f44fc5b8 00000000ffffb4e6 0000000000000000 ffffffff80efa270
[  262.667637]         a8000001f44fc868 0000000000000001 0000000000000000 ffffffff80ec69a0
[  262.675643]         a8000001f5da63a0 a800000107ca2020 a8000001f9214438 a8000001f5da63a0
[  262.683608]         a8000001f5121280 a8000001f90a3798 a8000001f7e20000 0000000000000000
[  262.691594]         0000000000000004 a800000107ca2020 a8000001f442ba70 ffffffff8011cd50
[  262.699579]         a8000001f9214438 ffffffff8011f684 0000000000000001 ffffffff8011cea8
[  262.707565]         a8000001f5da63a0 ffffffff804295a0 a8000001f5da63a0 0000001800000000
[  262.715576]         0000000000000000 a8000001f44fc5b8 ffffffff802e3f00 a800000107ca2038
[  262.723536]         a800000107ca2038 ffffffff8043987c 0000000000000000 a8000001f5da63a0
[  262.731522]         ...
[  262.734126] Call Trace:
[  262.736578] [<ffffffff8011c598>] __schedule_nobkl+0x278/0x900
[  262.742312] [<ffffffff8011cd50>] __schedule+0x48/0x80
[  262.747373] [<ffffffff8011cea8>] schedule+0x10/0x28
[  262.752185] [<ffffffff804295a0>] do_get_write_access+0x470/0x6a8
[  262.758220] [<ffffffff80434620>] jbd2_journal_get_write_access+0x30/0x58
[  262.764857] [<ffffffff804171a8>] __ext4_journal_get_write_access+0x48/0x88
[  262.771738] [<ffffffff803f94f0>] ext4_new_inode+0x290/0x1298
[  262.777367] [<ffffffff80406c40>] ext4_create+0xe8/0x1e0
[  262.782566] [<ffffffff80367c58>] vfs_create+0xf8/0x180
[  262.787705] [<ffffffff8036bcc8>] do_filp_open+0xab0/0xbb0
[  262.793069] [<ffffffff8035a060>] do_sys_open+0x78/0x170
[  262.798293] [<ffffffff80102fc4>] handle_sys64+0x44/0x60
[  262.803480] 

[  262.804984] INFO: task logrotate:2422 blocked for more than 120 seconds.
[  262.811674] Stack : 0000000000000000 0000000000000000 0000000000000000 ffffffff8040ebb8
[  262.819451]         a8000001f46b6738 00000000ffffafaf 0000000000000000 ffffffff80efa270
[  262.827436]         a8000001f46b69e8 0000000000000001 0000000000000000 ffffffff80ec69a0
[  262.835421]         ffffffff80ec6d48 a800000107c93020 a8000001f9062eb8 a8000001f9302950
[  262.843407]         a8000001f5121280 a8000001f90a3bb8 a8000001f7e20000 0000000000000000
[  262.851393]         0000000000000004 a800000107c93020 a8000001f4f73ba0 ffffffff8011cd50
[  262.859378]         a8000001f9062eb8 ffffffff8011f684 0000000000000001 ffffffff8011cea8
[  262.867364]         a8000001f9302950 ffffffff804295a0 a8000001f9302950 0000001800000000
[  262.875349]         0000000000000000 a8000001f46b6738 ffffffff802e3f00 a800000107c93038
[  262.883335]         a8000001f8b339d8 ffffffff8043987c 0000000000000000 a8000001f9302950
[  262.891321]         ...
[  262.893925] Call Trace:
[  262.896380] [<ffffffff8011c598>] __schedule_nobkl+0x278/0x900
[  262.902089] [<ffffffff8011cd50>] __schedule+0x48/0x80
[  262.907143] [<ffffffff8011cea8>] schedule+0x10/0x28
[  262.911985] [<ffffffff804295a0>] do_get_write_access+0x470/0x6a8
[  262.917994] [<ffffffff80434620>] jbd2_journal_get_write_access+0x30/0x58
[  262.924655] [<ffffffff804171a8>] __ext4_journal_get_write_access+0x48/0x88
[  262.931534] [<ffffffff803fc0f8>] ext4_reserve_inode_write+0x80/0xa8
[  262.937775] [<ffffffff804075c8>] ext4_orphan_add+0x130/0x298
[  262.943405] [<ffffffff804027a4>] ext4_setattr+0x1bc/0x3e0
[  262.948806] [<ffffffff80376f74>] notify_change+0x1a4/0x3a0
[  262.954255] [<ffffffff8035b140>] do_truncate+0x58/0xa8
[  262.959397] [<ffffffff8035b9cc>] SyS_ftruncate+0x104/0x160
[  262.964845] [<ffffffff80102fc4>] handle_sys64+0x44/0x60Thanks.

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