From: Brian King <brking@us.ibm.com>
To: linux-kernel@vger.kernel.org
Subject: call_usermodehelper hang
Date: Tue, 06 Apr 2004 13:11:03 -0500 [thread overview]
Message-ID: <4072F2B7.2070605@us.ibm.com> (raw)
I have been running into some kernel hangs due to call_usermodehelper. Looking
at the backtrace, it looks to me like there are deadlock issues with adding
devices from work queues. Attached is a sample backtrace from one of the
hangs I experienced. My question is why does call_usermodehelper do 2 different
things depending on whether or not it is called from the kevent task? It appears
that the simple way to fix the hang would be to never have call_usermodehelper
use a work_queue since it must be called from process context anyway, or
am I missing something?
0xc0000000017df300 1 0 0 0 D 0xc0000000017df7b0 swapper
SP(esp) PC(eip) Function(args)
0xc00000003fc9f460 0x0000000000000000 NO_SYMBOL or Userspace
0xc00000003fc9f4f0 0xc000000000058c40 .schedule +0xb4
0xc00000003fc9f5c0 0xc00000000005a464 .wait_for_completion +0x138
0xc00000003fc9f6c0 0xc00000000007c594 .call_usermodehelper +0x104
0xc00000003fc9f810 0xc00000000022d3e8 .kobject_hotplug +0x3c4
0xc00000003fc9f900 0xc00000000022d67c .kobject_add +0x134
0xc00000003fc9f9a0 0xc00000000012b3d8 .register_disk +0x70
0xc00000003fc9fa40 0xc00000000027dfe4 .add_disk +0x60
0xc00000003fc9fad0 0xc0000000002dc7dc .sd_probe +0x290
0xc00000003fc9fb80 0xc00000000026fbe8 .bus_match +0x94
0xc00000003fc9fc10 0xc00000000026ff70 .driver_attach +0x8c
0xc00000003fc9fca0 0xc000000000270104 .bus_add_driver +0x110
0xc00000003fc9fd50 0xc000000000270a18 .driver_register +0x38
0xc00000003fc9fdd0 0xc0000000002cd8f8 .scsi_register_driver +0x28
0xc00000003fc9fe50 0xc0000000004941d8 .init_sd +0x8c
0xc00000003fc9fee0 0xc00000000000c720 .init +0x25c
0xc00000003fc9ff90 0xc0000000000183ec .kernel_thread +0x4c
0xc00000003fab3380 4 1 0 0 D 0xc00000003fab3830 events/0
SP(esp) PC(eip) Function(args)
0xc00000003faaf6e0 0x0000000000000000 NO_SYMBOL or Userspace
0xc00000003faaf770 0xc000000000058c40 .schedule +0xb4
0xc00000003faaf840 0xc00000000022fa20 .rwsem_down_write_failed +0x14c
0xc00000003faaf910 0xc00000000026fed0 .bus_add_device +0x11c
0xc00000003faaf9b0 0xc00000000026e288 .device_add +0xd0
0xc00000003faafa50 0xc0000000002cdb00 .scsi_sysfs_add_sdev +0x8c
0xc00000003faafb00 0xc0000000002cbff8 .scsi_probe_and_add_lun +0xb04
0xc00000003faafc00 0xc0000000002ccca0 .scsi_add_device +0x90
0xc00000003faafcb0 0xc0000000002d9458 .ipr_worker_thread +0xc60
0xc00000003faafdc0 0xc00000000007cd9c .worker_thread +0x268
0xc00000003faafee0 0xc0000000000839cc .kthread +0x160
0xc00000003faaff90 0xc0000000000183ec .kernel_thread +0x4c
--
Brian King
eServer Storage I/O
IBM Linux Technology Center
--
Brian King
eServer Storage I/O
IBM Linux Technology Center
next reply other threads:[~2004-04-06 18:11 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-04-06 18:11 Brian King [this message]
2004-04-07 0:29 ` call_usermodehelper hang Andrew Morton
2004-04-07 6:11 ` Greg KH
2004-04-07 14:00 ` Brian King
2004-04-07 22:58 ` [PATCH] " Brian King
2004-04-08 22:47 ` Greg KH
2004-04-09 20:42 ` Brian King
2004-04-09 20:53 ` Greg KH
2004-04-09 21:05 ` Brian King
2004-04-09 21:15 ` Andrew Morton
2004-04-10 16:53 ` Greg KH
2004-04-10 20:11 ` Andrew Morton
2004-04-12 15:25 ` Brian King
2004-04-12 17:46 ` Andrew Morton
2004-04-16 17:55 ` Brian King
2004-04-12 18:49 ` Greg KH
2004-04-08 23:17 ` Chris Wright
2004-04-07 0:41 ` Chris Wright
2004-04-07 1:46 ` Brian King
[not found] <4072E2F5.9060604@us.ibm.com>
2004-04-16 8:52 ` Heiko Carstens
2004-04-16 14:06 ` Brian King
2005-02-25 17:17 Payasam Manohar
2005-02-25 18:06 ` Lee Revell
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4072F2B7.2070605@us.ibm.com \
--to=brking@us.ibm.com \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).