From: Steven Rostedt <rostedt@goodmis.org>
To: richard -rw- weinberger <richard.weinberger@gmail.com>
Cc: laijs@cn.fujitsu.com, LKML <linux-kernel@vger.kernel.org>,
user-mode-linux-devel@lists.sourceforge.net,
dvhart@linux.intel.com
Subject: Re: um: WARNING: at kernel/futex.c:786 __unqueue_futex
Date: Thu, 17 Mar 2011 10:08:56 -0400 [thread overview]
Message-ID: <1300370936.16880.96.camel@gandalf.stny.rr.com> (raw)
In-Reply-To: <AANLkTi=e+tM-WTerLmkZfLTQqKCLsJHVBgQ5sj+TMjc4@mail.gmail.com>
On Thu, 2011-03-17 at 13:25 +0100, richard -rw- weinberger wrote:
> Lai,
>
> Your commit 2e12978a
> (futex,plist: Pass the real head of the priority list to plist_del())
> triggers gazillions warnings on User Mode Linux (x86, Linus' tree as of today):
>
> ------------[ cut here ]------------
> WARNING: at kernel/futex.c:786 __unqueue_futex+0x12/0x16()
> Modules linked in:
> 27d4cce8: [<081c13fe>] dump_stack+0x1c/0x20
> 27d4cd00: [<08071aa0>] warn_slowpath_common+0x49/0x5f
> 27d4cd18: [<08071acb>] warn_slowpath_null+0x15/0x19
> 27d4cd28: [<0808fdb8>] __unqueue_futex+0x12/0x16
> 27d4cd38: [<0808fef3>] futex_wait+0x137/0x1ed
> 27d4cdd0: [<080910c3>] do_futex+0x78/0x7c4
> 27d4cedc: [<080918e6>] sys_futex+0xd7/0xed
> 27d4cf28: [<0805abf6>] handle_syscall+0x7a/0x98
> 27d4cf78: [<080685d9>] userspace+0x2c9/0x370
> 27d4cfe0: [<08058be5>] fork_handler+0x53/0x5b
> 27d4cffc: [<00000000>] 0x0
>
> ---[ end trace ed7709f235f82328 ]---
>
> !spin_is_locked(q->lock_ptr) in the WARN_ON() at line 786
> triggers the warnings.
Crap, I bet you are running CONFIG_SMP=n. I'll test this. We may need to
make that a WARN_ON_SMP().
-- Steve
>
> I'm not sure whether this shows a bug within UML
> or the WARN_ON() is wrong.
>
> What do you think?
>
next prev parent reply other threads:[~2011-03-17 14:08 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-17 12:25 um: WARNING: at kernel/futex.c:786 __unqueue_futex richard -rw- weinberger
2011-03-17 14:08 ` Steven Rostedt [this message]
2011-03-17 14:17 ` richard -rw- weinberger
2011-03-17 14:27 ` richard -rw- weinberger
2011-03-17 14:31 ` Steven Rostedt
2011-03-17 16:55 ` Steven Rostedt
2011-03-17 17:02 ` Eric Dumazet
2011-03-17 17:43 ` Geert Uytterhoeven
2011-03-17 18:22 ` Steven Rostedt
2011-03-17 18:32 ` Steven Rostedt
2011-03-17 18:16 ` Steven Rostedt
2011-03-17 18:25 ` Geert Uytterhoeven
2011-03-17 18:38 ` Steven Rostedt
2011-03-17 18:38 ` Eric Dumazet
2011-03-17 18:43 ` Steven Rostedt
2011-03-17 17:18 ` richard -rw- weinberger
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=1300370936.16880.96.camel@gandalf.stny.rr.com \
--to=rostedt@goodmis.org \
--cc=dvhart@linux.intel.com \
--cc=laijs@cn.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=richard.weinberger@gmail.com \
--cc=user-mode-linux-devel@lists.sourceforge.net \
/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