From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ben Hutchings <bhutchings@solarflare.com>
Subject: Re: alignment faults in 3.6
Date: Fri, 12 Oct 2012 16:04:14 +0100
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Cc: Benjamin LaHaise <bcrl@kvack.org>,
	Russell King - ARM Linux <linux@arm.linux.org.uk>,
	=?ISO-8859-1?Q?M=E5ns_Rullg=E5rd?= <mans@mansr.com>,
	Arnd Bergmann <arnd@arndb.de>,
	<linux-arm-kernel@lists.infradead.org>,
	David Laight <David.Laight@aculab.com>,
	<netdev@vger.kernel.org>, Jon Masters <jonathan@jonmasters.org>
To: Eric Dumazet <eric.dumazet@gmail.com>
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On Fri, 2012-10-12 at 16:48 +0200, Eric Dumazet wrote:
> On Fri, 2012-10-12 at 10:22 -0400, Benjamin LaHaise wrote:
> > On Fri, Oct 12, 2012 at 02:08:12PM +0200, Eric Dumazet wrote:
> > > So yes, we built network stack with the prereq that IP headers are
> > > aligned, but unfortunately many developers use x86 which doesnt care, so
> > > its possible some bugs are added.
> > 
> > x86 does have an alignment check flag that can be set in the flags register.  
> > Somehow, I doubt anyone would be willing to walk through all the noise the 
> > faults would likely trigger.
> 
> If this can be mapped to an event that can be used by perf tool, that
> might be useful ?

AC was so useless that it has now been reallocated to use by SMAP
<https://lwn.net/Articles/517251/>.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.