From: Nick Piggin <nickpiggin@yahoo.com.au>
To: Anton Altaparmakov <aia21@cam.ac.uk>
Cc: mingo@elte.hu, lkml <linux-kernel@vger.kernel.org>
Subject: Re: 2.6.7-rc1-bk: SMT scheduler bug / crashes on kernel boot
Date: Wed, 26 May 2004 22:10:08 +1000 [thread overview]
Message-ID: <40B48920.70206@yahoo.com.au> (raw)
In-Reply-To: <1085572902.2666.105.camel@imp.csi.cam.ac.uk>
Anton Altaparmakov wrote:
> On Wed, 2004-05-26 at 12:13, Nick Piggin wrote:
>
>>Anton Altaparmakov wrote:
>>
>>>Hi,
>>>
>>>Kernel 2.6.7-rc1-bk crashes on boot with a NULL pointer dereference.
>>>The kernel is running under VMware if that matters but I don't think it
>>>should. It was working fine with 2.6.6-rc3-bk kernels.
>>>
>>>I am afraid the only way I could capture the crash was to capture the
>>>vmware screen into a PNG image which is attached. Maybe I need to setup
>>>some OCR software for in the future... (-;
>>>
>>>The system running VMware is a P4 2.6Hz with Hyper threading enabled and
>>>/proc/cpuinfo shows two cpus:
>>
>>OK, thanks for that. It would be quite helpful if you edit
>>kernel/sched.c and turn the line #undef SCHED_DOMAIN_DEBUG into
>>#define SCHED_DOMAIN_DEBUG, then compile a kernel with debugging
>>info enabled.
>
>
> Looking at kernel/sched.c it already says #define, not #undef!
>
Oops, yes.
[snip]
> So the dereferencing of one of the two fails. Considering the offset is
> 0x18 in the NULL dereference it must be the (p)->prio that causes the
> oops and hence p must be NULL. I will leave you to figure out what that
> means...
>
Nice detective work.
It tried to dereference a NULL idle thread I'd say.
ie. the CPU hasn't been set up. Please try Ingo's patch.
next prev parent reply other threads:[~2004-05-26 12:12 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1085568719.2666.53.camel@imp.csi.cam.ac.uk>
2004-05-26 11:13 ` 2.6.7-rc1-bk: SMT scheduler bug / crashes on kernel boot Nick Piggin
[not found] ` <1085572902.2666.105.camel@imp.csi.cam.ac.uk>
2004-05-26 12:10 ` Nick Piggin [this message]
[not found] ` <1085569838.2666.60.camel@imp.csi.cam.ac.uk>
2004-05-26 11:28 ` Nick Piggin
[not found] ` <1085571285.2666.75.camel@imp.csi.cam.ac.uk>
2004-05-26 11:44 ` Ingo Molnar
2004-05-26 11:45 ` Nick Piggin
2004-05-26 15:54 Nakajima, Jun
2004-05-26 20:52 ` Zwane Mwaikambo
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=40B48920.70206@yahoo.com.au \
--to=nickpiggin@yahoo.com.au \
--cc=aia21@cam.ac.uk \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
/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