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From: Linus Torvalds <torvalds@linux-foundation.org>
To: david@lang.hm
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Borislav Petkov <bp@alien8.de>, Mike Galbraith <efault@gmx.de>,
	Mel Gorman <mgorman@suse.de>,
	Nikolay Ulyanitsky <lystor@gmail.com>,
	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>,
	Suresh Siddha <suresh.b.siddha@intel.com>
Subject: Re: 20% performance drop on PostgreSQL 9.2 from kernel 3.5.3 to 3.6-rc5 on AMD chipsets - bisected
Date: Thu, 27 Sep 2012 11:15:47 -0700	[thread overview]
Message-ID: <CA+55aFwSapFvbRJ-mCL+vUTvJwDufVPQR7q92KNA=eWiSKo2sg@mail.gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.02.1209271039500.8808@asgard.lang.hm>

On Thu, Sep 27, 2012 at 10:45 AM,  <david@lang.hm> wrote:
>
> For the initial starup of a new process, finding as idle and remote a core
> to start on (minimum sharing with existing processes) is probably the smart
> thing to do.

Actually, no.

It's *exec* that should go remote. New processes (fork, vfork or
clone) absolutely should *not* go remote at all.

vfork() should stay on the same CPU (synchronous wakeup), fork()
should possibly go SMT (likely exec in the near future will spread it
out), and clone should likely just stay close too.

           Linus

  parent reply	other threads:[~2012-09-27 18:16 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
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 [this message]
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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