linux-kernel - Re: Debugging hung tasks?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20110422205545.19196ada.rdunlap@xenotime.net>
Date:	Fri, 22 Apr 2011 20:55:45 -0700
From:	Randy Dunlap <rdunlap@...otime.net>
To:	Ben Greear <greearb@...delatech.com>
Cc:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: Debugging hung tasks?

On Fri, 22 Apr 2011 16:09:29 -0700 Ben Greear wrote:

> I am testing lots of NFS traffic against an over-loaded and slow file server.
> 
> I enabled the hung-task detection logic, and it's hitting after 180
> seconds.
> 
> First:  Is there any valid reason to have funky NFS cause a hung task?
> 
> Second: Why doesn't the hung-task panic logic print the stack trace of
>     the hung task?
>     Is this an option that can be enabled?

hung_task.c::check_hung_task() always calls sched_show_task() and
optionally does the panic:

	if (sysctl_hung_task_panic)
		panic("hung_task: blocked tasks");

sched.c::sched_show_task() calls show_stack(), which should be doing what
you are asking for AFAICT.  What kernel version are you using?

---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/