ISST-LTE:Ubuntu15.04: task aio-stress:12277 blocked for more than 120 seconds.

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== Comment: #0 - Hemant Kumar <email address hidden> - 2015-04-13 01:29:44 ==
Defect Description:
===============

I am having one ubuntu 15.04 LE lpar running with regression run(BASE/IO/TCP). After some hours of run i was not able to get virtual terminal of lpar but i am able to login via ssh. I did ssh and i saw these stack traces in dmesg:

[14889.385371] blk_update_request: critical target error, dev dm-10, sector 13842352
[14889.385389] dm-16: WRITE SAME failed. Manually zeroing.
[16080.244960] INFO: task aio-stress:12275 blocked for more than 120 seconds.
[16080.244976] Not tainted 3.19.0-12-generic #12-Ubuntu
[16080.244979] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[16080.244983] aio-stress D 00003fff7e420818 0 12275 12092 0x00040000
[16080.244985] Call Trace:
[16080.244989] [c0000007704633f0] [c000000000015a4c] __switch_to+0x1fc/0x350
[16080.244992] [c000000770463440] [c000000000a3601c] __schedule+0x37c/0x8d0
[16080.244994] [c000000770463670] [c000000000a3a8b4] schedule_timeout+0x254/0x2f0
[16080.244996] [c000000770463760] [c000000000a377dc] wait_for_common+0xec/0x240
[16080.244998] [c0000007704637e0] [c0000000002ff1c8] writeback_inodes_sb_nr+0xb8/0xe0
[16080.245000] [c000000770463880] [c0000000002ffa78] try_to_writeback_inodes_sb_nr+0x98/0xd0
[16080.245002] [c0000007704638c0] [c0000000003774bc] ext4_nonda_switch+0xdc/0xf0
[16080.245004] [c000000770463900] [c00000000037e340] ext4_da_write_begin+0x90/0x3d0
[16080.245006] [c0000007704639c0] [c0000000002134f4] generic_perform_write+0xf4/0x280
[16080.245008] [c000000770463a60] [c0000000002159e0] __generic_file_write_iter+0x2a0/0x430
[16080.245009] [c000000770463ac0] [c000000000371428] ext4_file_write_iter+0x118/0x480
[16080.245011] [c000000770463b80] [c000000000329c78] aio_run_iocb+0x268/0x450
[16080.245013] [c000000770463ce0] [c00000000032afc4] do_io_submit+0x294/0x670
[16080.245015] [c000000770463e30] [c000000000009258] syscall_exit+0x0/0x98
[16080.245017] INFO: task aio-stress:12276 blocked for more than 120 seconds.
[16080.245022] Not tainted 3.19.0-12-generic #12-Ubuntu
[16080.245025] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

I am running IO regression run from last many weeks but i have not seen this issue in any previous kernel.

root@riverlp1:~# cat /etc/issue
Ubuntu Vivid Vervet (development branch) \n \l

root@riverlp1:~# uname -a
Linux riverlp1 3.19.0-12-generic #12-Ubuntu SMP Fri Apr 3 04:03:54 UTC 2015 ppc64le ppc64le ppc64le GNU/Linux
root@riverlp1:~#

Contact Info: <email address hidden>

== Comment: #1 - Hemant Kumar <email address hidden> - 2015-04-13 01:32:40 ==

== Comment: #2 - Hemant Kumar <email address hidden> - 2015-04-13 01:35:52 ==

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Default Comment by Bridge

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Default Comment by Bridge

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1443325/+editstatus and add the package name in the text box next to the word Package.

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------- Comment From <email address hidden> 2015-04-24 16:56 EDT-------
Any update on this bug?

[Mathieu Trudel-Lapierre (cyphermox)]

Reassigning to the linux package; the kernel team would more likely know if there is a fix available for this.

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------- Comment From <email address hidden> 2015-06-02 06:49 EDT-------
Any update on this bug?

[Chris J Arges (arges)]

I don't see anything obvious in the backlog. Is it possible to test a v4.1 kernel to see if this was fixed recently?
In addition is this also present on PowerNV systems as well?

[Mauricio Faria de Oliveira (mfo)]

There's been difficulty in reproducing this problem. Closing as invalid for now. Thanks!