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From: David Miller <davem@davemloft.net>
To: linas@austin.ibm.com
Cc: linuxppc-dev@ozlabs.org, netdev@vger.kernel.org, mingo@elte.hu,
	tglx@linutronix.de
Subject: Re: RT patches expose netdev race [was Re: [RFC] [patch 2/2] powerpc 2.6.21-rt1: fix kernel hang and/or panic
Date: Wed, 16 May 2007 17:41:01 -0700 (PDT)	[thread overview]
Message-ID: <20070516.174101.45179259.davem@davemloft.net> (raw)
In-Reply-To: <20070517001801.GB4325@austin.ibm.com>

From: linas@austin.ibm.com (Linas Vepstas)
Date: Wed, 16 May 2007 19:18:02 -0500

> Hi,
> 
> On Tue, May 15, 2007 at 08:09:02PM +1000, Benjamin Herrenschmidt wrote:
> > On Tue, 2007-05-15 at 17:47 +0900, Tsutomu OWA wrote:
> > >   I encountered the following error when doing netperf from other machine 
> > > to Celleb running RT kernel.  PREEPT_NONE kernel works just fine as well.
> > 
> > Hrm... sounds a bit weird. I wonder if there's a locking bug in the
> > driver in the first place.
> > 
> > Linas, what's your take ?
> 
> Heh. I almost deleted the entire email thread cause it
> didn't say "spidernet" in the subject line. :-)
> Seriously, I really almost did ....
> 
> Since this is a long email; let me put a summary up front:
> I think the RT/premption patches are exposing some sort
> of race in the ip header handling code. The rest of the 
> note is forensics pointing to this.

skb->head should never ever be NULL.

  reply	other threads:[~2007-05-17  0:40 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-15  8:35 [RFC] [patch 0/2] powerpc 2.6.21-rt1: fix kernel hang and/or panic Tsutomu OWA
2007-05-15  8:44 ` [RFC] [patch 1/2] " Tsutomu OWA
2007-05-15  8:47 ` [RFC] [patch 2/2] " Tsutomu OWA
2007-05-15 10:09   ` Benjamin Herrenschmidt
2007-05-17  0:18     ` RT patches expose netdev race [was " Linas Vepstas
2007-05-17  0:41       ` David Miller [this message]
2007-05-17 23:52         ` Linas Vepstas
2007-05-18  5:36           ` Tsutomu OWA

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