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From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>,
	Nikolay Ulyanitsky <lystor@gmail.com>,
	Mike Galbraith <efault@gmx.de>,
	linux-kernel@vger.kernel.org,
	Andreas Herrmann <andreas.herrmann3@amd.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>
Subject: Re: 20% performance drop on PostgreSQL 9.2 from kernel 3.5.3 to 3.6-rc5 on AMD chipsets - bisected
Date: Fri, 14 Sep 2012 23:56:17 +0200	[thread overview]
Message-ID: <1347659777.7172.97.camel@twins> (raw)
In-Reply-To: <CA+55aFz6SxLEr0MNubz7rcwcqki7EM33Vp-q3KFEvuLG6a61ZQ@mail.gmail.com>

On Fri, 2012-09-14 at 14:44 -0700, Linus Torvalds wrote:
> On Fri, Sep 14, 2012 at 2:40 PM, Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
> >
> > The problem the patch is trying to address is not having to scan an
> > entire package for idle cores on every wakeup now that packages are
> > getting stupid big.
> 
> No, it does something *else* too. That whole "left-right" logic to
> (according to the commit message) "prevent bouncing" is entirely new,
> afaik.
> 
> So it is *not* just about avoiding to have to scan the whole package.
> It changes actual semantics too. No?

Both things change semantics, not looking at the entire package is new
too. But yeah I guess you could look at the exact cross-stitching as an
enhancement to the 'idle_buggy' thing.



  reply	other threads:[~2012-09-14 21:56 UTC|newest]

Thread overview: 115+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-14  7:47 20% performance drop on PostgreSQL 9.2 from kernel 3.5.3 to 3.6-rc5 on AMD chipsets Nikolay Ulyanitsky
2012-09-14 18:40 ` Borislav Petkov
2012-09-14 18:51   ` Borislav Petkov
2012-09-14 21:27 ` 20% performance drop on PostgreSQL 9.2 from kernel 3.5.3 to 3.6-rc5 on AMD chipsets - bisected Borislav Petkov
2012-09-14 21:40   ` Peter Zijlstra
2012-09-14 21:44     ` Linus Torvalds
2012-09-14 21:56       ` Peter Zijlstra [this message]
2012-09-14 21:59         ` Peter Zijlstra
2012-09-15  3:57           ` Mike Galbraith
2012-09-14 22:01         ` Linus Torvalds
2012-09-14 22:10           ` Peter Zijlstra
2012-09-14 22:20             ` Linus Torvalds
2012-09-14 22:14           ` Borislav Petkov
2012-09-14 21:45     ` Borislav Petkov
2012-09-14 21:42   ` Linus Torvalds
2012-09-15  3:33     ` Mike Galbraith
2012-09-15 16:16       ` Andi Kleen
2012-09-15 16:36         ` Mike Galbraith
2012-09-15 17:08           ` richard -rw- weinberger
2012-09-16  4:48             ` Mike Galbraith
2012-09-15 21:32           ` Alan Cox
2012-09-16  4:35             ` Mike Galbraith
2012-09-16 19:57               ` Linus Torvalds
2012-09-17  8:08                 ` Mike Galbraith
2012-09-17 10:07                   ` Ingo Molnar
2012-09-17 10:47                     ` Mike Galbraith
2012-09-17 14:39                     ` Andi Kleen
2012-09-19 12:35               ` Mike Galbraith
2012-09-19 14:54                 ` Ingo Molnar
2012-09-19 15:23                   ` Mike Galbraith
2012-09-24 15:00     ` Mel Gorman
2012-09-24 15:23       ` Nikolay Ulyanitsky
2012-09-24 15:53         ` Borislav Petkov
2012-09-24 15:30       ` Peter Zijlstra
2012-09-24 15:51         ` Mike Galbraith
2012-09-24 15:52         ` Linus Torvalds
2012-09-24 16:07           ` Peter Zijlstra
2012-09-24 16:33             ` Linus Torvalds
2012-09-24 16:54               ` Peter Zijlstra
2012-09-25 12:10                 ` Hillf Danton
2012-09-24 16:12           ` Peter Zijlstra
2012-09-24 16:30             ` Linus Torvalds
2012-09-24 16:52               ` Borislav Petkov
2012-09-24 16:54               ` Peter Zijlstra
2012-09-24 17:44                 ` Peter Zijlstra
2012-09-25 13:23                   ` Mel Gorman
2012-09-25 14:36                     ` Peter Zijlstra
2012-09-24 18:26                 ` Mike Galbraith
2012-09-24 19:12                   ` Linus Torvalds
2012-09-24 19:20                     ` Borislav Petkov
2012-09-25  1:57                       ` Mike Galbraith
2012-09-25  2:11                         ` Linus Torvalds
2012-09-25  2:49                           ` Mike Galbraith
2012-09-25  3:10                             ` Linus Torvalds
2012-09-25  3:20                               ` Mike Galbraith
2012-09-25  3:32                                 ` Linus Torvalds
2012-09-25  3:43                                   ` Mike Galbraith
2012-09-25 11:58                           ` Peter Zijlstra
2012-09-25 13:17                             ` Borislav Petkov
2012-09-25 17:00                               ` Borislav Petkov
2012-09-25 17:21                                 ` Linus Torvalds
2012-09-25 18:42                                   ` Borislav Petkov
2012-09-25 19:08                                     ` Linus Torvalds
2012-09-26  2:23                                     ` Mike Galbraith
2012-09-26 17:17                                       ` Borislav Petkov
2012-09-26  2:00                                   ` Mike Galbraith
2012-09-26  2:22                                     ` Linus Torvalds
2012-09-26  2:42                                       ` Mike Galbraith
2012-09-26 17:15                                       ` Borislav Petkov
2012-09-26 16:32                                   ` Borislav Petkov
2012-09-26 18:19                                     ` Linus Torvalds
2012-09-26 21:37                                       ` Borislav Petkov
2012-09-27  5:09                                         ` Mike Galbraith
2012-09-27  5:18                                           ` Borislav Petkov
2012-09-27  5:44                                             ` Mike Galbraith
2012-09-27  5:47                                           ` Ingo Molnar
2012-09-27  5:59                                             ` Ingo Molnar
2012-09-27  6:34                                             ` Mike Galbraith
2012-09-27  6:41                                               ` Ingo Molnar
2012-09-27  6:54                                                 ` Mike Galbraith
2012-09-27  7:10                                                   ` Ingo Molnar
2012-09-27 16:25                                                     ` Borislav Petkov
2012-09-27 17:44                                                     ` Linus Torvalds
2012-09-27 18:05                                                       ` Borislav Petkov
2012-09-27 18:19                                                         ` Linus Torvalds
2012-09-27 18:29                                                           ` Peter Zijlstra
2012-09-27 19:24                                                             ` Borislav Petkov
2012-09-28  3:50                                                               ` Mike Galbraith
2012-09-28 12:30                                                                 ` Borislav Petkov
2012-09-27 19:40                                                             ` Linus Torvalds
2012-09-28  4:13                                                               ` Mike Galbraith
2012-09-28  8:37                                                               ` Peter Zijlstra
2012-09-27  7:17                                         ` david
2012-09-27  7:55                                           ` Mike Galbraith
2012-09-27 10:20                                           ` Borislav Petkov
2012-09-27 13:38                                             ` Mike Galbraith
2012-09-27 16:55                                             ` david
2012-09-27  4:32                                       ` Mike Galbraith
2012-09-27  8:21                                       ` Peter Zijlstra
2012-09-27 16:48                                         ` david
2012-09-27 17:38                                           ` Peter Zijlstra
2012-09-27 17:45                                             ` david
2012-09-27 18:09                                               ` Peter Zijlstra
2012-09-27 18:15                                               ` Linus Torvalds
2012-09-27 18:24                                               ` Borislav Petkov
2012-09-25  1:39                     ` Mike Galbraith
2012-09-25 21:11                     ` Suresh Siddha
2012-09-25  4:16       ` Mike Galbraith
2012-09-15  4:11   ` Mike Galbraith
     [not found]     ` <CA+55aFz1A7HbMYS9o-GTS5Zm=Xx8MUD7cR05GMVo--2E34jcgQ@mail.gmail.com>
2012-09-15  4:42       ` Mike Galbraith
2012-09-15 10:44     ` Borislav Petkov
2012-09-15 14:47       ` Mike Galbraith
2012-09-15 15:18         ` Borislav Petkov
2012-09-15 16:13           ` Mike Galbraith
2012-09-15 19:44             ` Borislav Petkov

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