From: Benjamin LaHaise <bcrl@kvack•org>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: "Russell King - ARM Linux" <linux@arm•linux.org.uk>,
"Måns Rullgård" <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>
Subject: Re: alignment faults in 3.6
Date: Fri, 12 Oct 2012 11:00:45 -0400 [thread overview]
Message-ID: <20121012150045.GH5453@kvack.org> (raw)
In-Reply-To: <1350053300.21172.12319.camel@edumazet-glaptop>
On Fri, Oct 12, 2012 at 04:48:20PM +0200, Eric Dumazet wrote:
> > 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 ?
There are performance counters for the various different types of alignment
faults supported by perf. Modern x86 makes the vast majority of unaligned
accesses very low overhead -- the only ones that really hurt are those
straddling different vm pages, but even those have little cost compared to
obsolete microarchitectures (*cough* P4 *cough*).
-ben
--
"Thought is the essence of where you are now."
next prev parent reply other threads:[~2012-10-12 15:00 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <506E1762.3010601@gmail.com>
[not found] ` <CANLjY-no-L9=LRCvCetC5XCHicOoSWOfRZmUd7itAiUHWBhAyw@mail.gmail.com>
[not found] ` <CAG5Tg6Wuybruc31x1eh6mFafsg=7cOgYLgpZUBuJUo75ap3osQ@mail.gmail.com>
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[not found] ` <CAG5Tg6V0Vj9HTy3=AU-q+Qa3DuJs6R1Kw+3uOWU_jOGfkgyXzw@mail.gmail.com>
[not found] ` <20121005071216.GD4625@n2100.arm.linux.org.uk>
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[not found] ` <506EEFBB.3060705@gmail.com>
[not found] ` <507619FA.6080001@jonmasters.org>
2012-10-11 2:27 ` alignment faults in 3.6 Måns Rullgård
2012-10-11 2:34 ` Jon Masters
2012-10-11 8:21 ` David Laight
2012-10-11 8:53 ` Russell King - ARM Linux
2012-10-11 9:45 ` Måns Rullgård
2012-10-11 10:00 ` Eric Dumazet
2012-10-11 10:20 ` Måns Rullgård
2012-10-11 10:22 ` Eric Dumazet
2012-10-11 10:32 ` Russell King - ARM Linux
2012-10-11 10:49 ` Eric Dumazet
2012-10-11 10:56 ` Maxime Bizon
2012-10-11 11:28 ` Eric Dumazet
2012-10-11 11:47 ` Maxime Bizon
2012-10-11 11:54 ` Eric Dumazet
2012-10-11 12:00 ` Eric Dumazet
2012-10-11 12:51 ` Maxime Bizon
2012-10-11 12:59 ` Eric Dumazet
2012-10-11 12:28 ` Arnd Bergmann
2012-10-11 12:40 ` Eric Dumazet
2012-10-11 13:20 ` Rob Herring
2012-10-11 13:32 ` Måns Rullgård
2012-10-11 13:35 ` Arnd Bergmann
2012-10-11 13:47 ` Eric Dumazet
2012-10-11 15:23 ` Rob Herring
2012-10-11 15:39 ` David Laight
2012-10-11 16:18 ` Måns Rullgård
2012-10-12 8:11 ` Arnd Bergmann
2012-10-12 9:03 ` Russell King - ARM Linux
2012-10-12 10:04 ` Eric Dumazet
2012-10-12 12:24 ` Russell King - ARM Linux
2012-10-12 11:00 ` Måns Rullgård
2012-10-12 11:07 ` Russell King - ARM Linux
2012-10-12 11:18 ` Måns Rullgård
2012-10-12 11:44 ` Russell King - ARM Linux
2012-10-12 12:08 ` Eric Dumazet
2012-10-12 14:22 ` Benjamin LaHaise
2012-10-12 14:36 ` David Laight
2012-10-12 14:48 ` Eric Dumazet
2012-10-12 15:00 ` Benjamin LaHaise [this message]
2012-10-12 15:04 ` Ben Hutchings
2012-10-12 15:47 ` David Laight
2012-10-12 16:13 ` Ben Hutchings
2012-10-12 12:16 ` Måns Rullgård
2012-10-12 11:19 ` Russell King - ARM Linux
2012-10-11 16:15 ` Eric Dumazet
2012-10-11 16:59 ` Catalin Marinas
2012-10-11 10:16 ` David Laight
2012-10-11 10:46 ` Måns Rullgård
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