From: Andrew Morton <akpm@linux-foundation.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
bugzilla-daemon@bugzilla.kernel.org,
bugme-daemon@bugzilla.kernel.org, ant.starikov@gmail.com,
Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [Bugme-new] [Bug 15618] New: 2.6.18->2.6.32->2.6.33 huge regression in performance
Date: Tue, 23 Mar 2010 11:13:51 -0700 [thread overview]
Message-ID: <20100323111351.756c8752.akpm@linux-foundation.org> (raw)
In-Reply-To: <20100323173409.GA24845@elte.hu>
On Tue, 23 Mar 2010 18:34:09 +0100
Ingo Molnar <mingo@elte.hu> wrote:
>
> It shows a very brutal amount of page fault invoked mmap_sem spinning
> overhead.
>
Yes. Note that we fall off a cliff at nine threads on a 16-way. As
soon as a core gets two threads scheduled onto it? Probably triggered
by an MM change, possibly triggered by a sched change which tickled a
preexisting MM shortcoming. Who knows.
Anton, we have an executable binary in the bugzilla report but it would
be nice to also have at least a description of what that code is
actually doing. A quick strace shows quite a lot of mprotect activity.
A pseudo-code walkthrough, perhaps?
Thanks.
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next prev parent reply other threads:[~2010-03-23 18:14 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <bug-15618-10286@https.bugzilla.kernel.org/>
2010-03-23 14:22 ` Andrew Morton
2010-03-23 17:34 ` Ingo Molnar
2010-03-23 17:45 ` Linus Torvalds
2010-03-23 17:57 ` Anton Starikov
2010-03-23 18:00 ` Ingo Molnar
2010-03-23 18:03 ` Anton Starikov
2010-03-23 18:21 ` Andrew Morton
2010-03-23 18:25 ` Anton Starikov
2010-03-23 19:22 ` Robin Holt
2010-03-23 19:30 ` Anton Starikov
2010-03-23 19:49 ` Robin Holt
2010-03-23 19:57 ` Robin Holt
2010-03-23 19:50 ` Anton Starikov
2010-03-23 19:52 ` Linus Torvalds
2010-03-24 16:40 ` Roland Dreier
2010-03-26 3:24 ` Anton Starikov
2010-03-23 19:14 ` Anton Starikov
2010-03-23 19:17 ` Peter Zijlstra
2010-03-23 19:42 ` Anton Starikov
2010-03-23 19:54 ` Linus Torvalds
2010-03-23 20:43 ` Anton Starikov
2010-03-23 23:04 ` Linus Torvalds
2010-03-23 23:19 ` Anton Starikov
2010-03-23 23:36 ` Ingo Molnar
2010-03-23 23:55 ` Linus Torvalds
2010-03-24 0:03 ` Anton Starikov
2010-03-24 2:15 ` Andi Kleen
2010-03-24 3:00 ` Linus Torvalds
2010-04-19 18:19 ` Greg KH
2010-03-23 18:13 ` Andrew Morton [this message]
2010-03-23 18:19 ` Anton Starikov
2010-03-23 18:27 ` Ingo Molnar
2010-03-23 21:19 ` Anton Starikov
2010-04-02 18:57 ` Lee Schermerhorn
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