From: Ben Hutchings <ben@decadent.org.uk>
To: sparclinux@vger.kernel.org
Subject: Re: [sparc] BUG: NMI Watchdog detected LOCKUP on CPU0
Date: Sat, 07 Apr 2012 17:21:38 +0000 [thread overview]
Message-ID: <1333819298.7150.63.camel@deadeye> (raw)
[-- Attachment #1: Type: text/plain, Size: 1504 bytes --]
Summary for the SPARC maintainers:
The NMI watchdog is firing on Sunfire 280R and Sun Blade2500 systems
with one or both processors in cheetah_xcall_deliver(). This has been
seen under 3.0, 3.2 and 3.3 and seems to be associated with disk I/O.
Full bug log is at: http://bugs.debian.org/648766
On Tue, 2012-04-03 at 20:56 -0400, Kieron Gillespie wrote:
> I have also noticed, that if I am reading the trace correctly that in
> both of my cases, and the original bug submitter's, and a bug posted on
> old.nabble.com's case the crash always seems to happen when one CPU is
> doing cheetah_xcall_deliver, and the other CPU is in the same
> instruction in tl0_irq15. Here is a link to the post.
[...]
tl0_irq15 seems to be part of the NMI watchdog (for detecting that the
kernel has hung), so you should always see that in a backtrace when the
NMI watchdog fires. It's not part of the problem.
cheetah_xcall_deliver() does appear to be relevant to the problem and it
looks like it could loop indefinitely - though presumably only if a
processor is behaving strangely? It appears to periodically enable and
disable interrupts, but then I'm not sure how the PSTATE.IE and PIL
interrupt control fields interact and I don't think this will reset the
NMI watchdog. In any case, it seems like there's a serious problem if
it's looping for a long time, whether or not interrupts remain disabled.
Ben.
--
Ben Hutchings
Larkinson's Law: All laws are basically false.
[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 828 bytes --]
next reply other threads:[~2012-04-07 17:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-07 17:21 Ben Hutchings [this message]
2012-04-07 17:40 ` [sparc] BUG: NMI Watchdog detected LOCKUP on CPU0 David Miller
2012-04-08 21:12 ` Ben Hutchings
2012-04-08 21:49 ` David Miller
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=1333819298.7150.63.camel@deadeye \
--to=ben@decadent.org.uk \
--cc=sparclinux@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.