From: Joe Buehler <aspam@cox•net>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: netdev@vger•kernel.org
Subject: Re: kernel panic in fib_rules_lookup [2.6.27.7 vendor-patched]
Date: Sat, 23 Oct 2010 11:33:41 -0400 [thread overview]
Message-ID: <4CC30055.5040509@cox.net> (raw)
In-Reply-To: <1287846669.2658.247.camel@edumazet-laptop>
Eric Dumazet wrote:
>
> Did that... Hmm...
>
> I am wondering if smp_rcu_assign_pointer() (or more precisely smp_wmb())
> is correctly implemented on octeon platform.
>
> Try to add in fib_nl_newrule() right after the kzalloc bloc :
>
> rule = kzalloc(ops->rule_size, GFP_KERNEL);
> if (rule == NULL) {
> err = -ENOMEM;
> goto errout;
> }
> + rule->list.next = LIST_POISON1;
> + rule->list.prev = LIST_POISON2;
>
>
> So that we can actually see if the NULL dereference bug you hit becomes
> a "LIST_POISON1" dereference bug...
>
>
>
Thanks -- I'll try it when I'm back in the office Tuesday.
It is always possible that there is some issue with the Octeon memory
barrier stuff, but I would think that the system would be much more
unstable than it is -- we're really beating on a dual CPU LINUX instance
that has Java and C++ apps running and also doing some network I/O.
My strategy at this point is logging events to memory and dumping the
log to the console at the time of the panic. I might be able to figure
out the sequence of events causing the crash.
The load test that causes the panic is using several dozen TAP
interfaces, ifconfig'd up/down every 10 seconds or so, with
source-routes, DNAT and SNAT being set up and taken down also.
Joe Buehler
next prev parent reply other threads:[~2010-10-23 15:33 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-12 17:14 kernel panic in fib_rules_lookup [2.6.27.7 vendor-patched] Joe Buehler
2010-10-12 17:40 ` Eric Dumazet
2010-10-13 11:18 ` Joe Buehler
2010-10-20 17:43 ` Joe Buehler
2010-10-20 22:05 ` Eric Dumazet
2010-10-22 20:30 ` Joe Buehler
2010-10-23 3:44 ` Eric Dumazet
2010-10-23 15:11 ` Eric Dumazet
2010-10-23 15:24 ` Eric Dumazet
2010-10-23 15:40 ` Joe Buehler
2010-10-23 16:07 ` Eric Dumazet
2010-10-23 15:33 ` Joe Buehler [this message]
2010-10-23 16:35 ` Eric Dumazet
2010-10-23 17:37 ` "Oleg A. Arkhangelsky"
2010-10-23 19:44 ` Eric Dumazet
2010-10-26 18:43 ` David Miller
2010-10-26 13:29 ` Joe Buehler
2010-10-26 13:36 ` Eric Dumazet
2010-10-26 13:53 ` Joe Buehler
2010-10-26 13:58 ` Eric Dumazet
2010-10-26 14:33 ` Eric Dumazet
2010-10-26 14:41 ` Joe Buehler
2010-10-27 21:01 ` Joe Buehler
2010-10-27 21:05 ` Eric Dumazet
2010-12-02 13:36 ` Joe Buehler
2010-12-02 14:04 ` Eric Dumazet
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