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From: Ingo Molnar <mingo@elte.hu>
To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org,
	eric.dumazet@gmail.com, arjan@linux.intel.com,
	torvalds@linux-foundation.org, johnstul@us.ibm.com,
	a.p.zijlstra@chello.nl, schwidefsky@de.ibm.com,
	arjan@infradead.org, tglx@linutronix.de
Cc: linux-tip-commits@vger.kernel.org
Subject: Re: [tip:sched/urgent] x86: Provide an alternative() based cmpxchg64()
Date: Wed, 30 Sep 2009 22:58:08 +0200	[thread overview]
Message-ID: <20090930205808.GC24862@elte.hu> (raw)
In-Reply-To: <tip-e87aaa7b6d80474ec07a2d2be3f50ef574ffe36c@git.kernel.org>


* tip-bot for Arjan van de Ven <arjan@infradead.org> wrote:

> Commit-ID:  e87aaa7b6d80474ec07a2d2be3f50ef574ffe36c
> Gitweb:     http://git.kernel.org/tip/e87aaa7b6d80474ec07a2d2be3f50ef574ffe36c
> Author:     Arjan van de Ven <arjan@infradead.org>
> AuthorDate: Wed, 30 Sep 2009 17:07:54 +0200
> Committer:  Ingo Molnar <mingo@elte.hu>
> CommitDate: Wed, 30 Sep 2009 22:35:44 +0200
> 
> x86: Provide an alternative() based cmpxchg64()
> 
> cmpxchg64() today generates, to quote Linus, "barf bag" code.
> 
> cmpxchg64() is about to get used in the scheduler to a bug there,
> but it's a prerequisite that cmpxchg64() first be made non-sucking.
> 
> This patch turns cmpxchg64() into an efficient implementation that
> uses the alternative() mechanism to just use the raw instruction on
> all modern systens

The changelog above has 3 typos so i fixed that. The push will generate 
the hopefully-final version of these patches.

Note, i slightly updated Linus's version of the old-CPU emu code with 
Eric's micro-optimization.

	Ingo

  reply	other threads:[~2009-09-30 20:58 UTC|newest]

Thread overview: 79+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-09-27 22:34 Linux 2.6.32-rc1 Linus Torvalds
2009-09-27 23:44 ` Stephen Rothwell
2009-09-27 23:48   ` Diego Calleja
2009-09-27 23:52   ` Linus Torvalds
2009-09-28  0:17     ` Stephen Rothwell
2009-09-28  7:07 ` Eric Dumazet
2009-09-28 15:39   ` Linus Torvalds
2009-09-28 17:15     ` Martin Schwidefsky
2009-09-28 18:41       ` Eric Dumazet
2009-09-28 20:56         ` Martin Schwidefsky
2009-09-29 20:42         ` Eric Dumazet
2009-09-29 21:17           ` Linus Torvalds
2009-09-29 21:22             ` Arjan van de Ven
2009-09-29 21:56               ` Linus Torvalds
2009-09-30 15:07                 ` Arjan van de Ven
2009-09-30 15:27                   ` Eric Dumazet
2009-09-30 15:31                     ` Arjan van de Ven
2009-10-01  0:42                       ` Yuhong Bao
2009-09-30 15:57                   ` Eric Dumazet
2009-09-30 16:13                     ` Arjan van de Ven
2009-09-30 16:14                     ` Linus Torvalds
2009-09-30 18:53                       ` Ingo Molnar
2009-09-30 22:03                         ` [GIT PULL] scheduler fixes Ingo Molnar
2009-10-01  0:42                           ` Linus Torvalds
2009-10-01  0:57                             ` Linus Torvalds
2009-10-01  5:30                               ` Eric Dumazet
2009-10-01  6:11                                 ` Ingo Molnar
2009-10-01  6:18                                   ` Eric Dumazet
2009-10-01  6:42                                     ` Ingo Molnar
2009-10-01  6:59                                       ` Eric Dumazet
2009-10-01  7:28                                       ` Sam Ravnborg
2009-10-01  6:49                                 ` [tip:x86/urgent] x86: Don't generate cmpxchg8b_emu if CONFIG_X86_CMPXCHG64=y tip-bot for Eric Dumazet
2009-10-01  6:40                               ` [tip:x86/urgent] x86: Optimize cmpxchg64() at build-time some more tip-bot for Linus Torvalds
2009-10-02 16:40                               ` [GIT PULL] scheduler fixes Yuhong Bao
2009-10-01  6:05                             ` Ingo Molnar
2009-09-30 16:14                     ` Linux 2.6.32-rc1 Cyrill Gorcunov
2009-09-30 16:55                   ` Stefan Richter
2009-09-30 17:08                     ` Linus Torvalds
2009-09-30 17:40                       ` Stefan Richter
2009-09-30 19:32                   ` Ingo Molnar
2009-09-30 19:35                     ` Ingo Molnar
2009-09-30 20:16                     ` Eric Dumazet
2009-09-30 20:20                       ` Linus Torvalds
2009-09-30 20:22                         ` Ingo Molnar
2009-09-30 20:38                           ` Ingo Molnar
2009-10-01  7:18                             ` Arjan van de Ven
2009-09-30 19:37                   ` [tip:sched/urgent] x86: Provide an alternative() based cmpxchg64() tip-bot for Arjan van de Ven
2009-09-30 19:37                   ` [tip:sched/urgent] sched_clock: Fix atomicity/continuity bug by using cmpxchg64() tip-bot for Arjan van de Ven
2009-09-30 19:39                     ` Ingo Molnar
2009-09-30 19:39                   ` tip-bot for Eric Dumazet
2009-09-30 20:19                   ` Linux 2.6.32-rc1 Linus Torvalds
2009-09-30 20:24                     ` Eric Dumazet
2009-09-30 20:41                       ` Linus Torvalds
2009-09-30 20:49                         ` Ingo Molnar
2009-09-30 20:53                           ` Eric Dumazet
2009-09-30 21:00                             ` Ingo Molnar
2009-09-30 20:54                         ` Linus Torvalds
2009-09-30 21:53                         ` David Miller
2009-10-01 12:48                         ` Christoph Hellwig
2009-10-01 16:08                           ` Valdis.Kletnieks
2009-10-05 14:39                             ` Peter Zijlstra
2009-09-30 20:40                   ` [tip:sched/urgent] x86: Provide an alternative() based cmpxchg64() tip-bot for Arjan van de Ven
2009-09-30 20:58                     ` Ingo Molnar [this message]
2009-09-30 20:40                   ` [tip:sched/urgent] sched_clock: Fix atomicity/continuity bug by using cmpxchg64() tip-bot for Eric Dumazet
2009-09-30 20:55                   ` [tip:sched/urgent] x86: Provide an alternative() based cmpxchg64() tip-bot for Arjan van de Ven
2009-09-30 20:55                   ` [tip:sched/urgent] sched_clock: Fix atomicity/continuity bug by using cmpxchg64() tip-bot for Eric Dumazet
2009-09-30 21:00                   ` [tip:sched/urgent] x86: Provide an alternative() based cmpxchg64() tip-bot for Arjan van de Ven
2009-09-30 21:01                   ` [tip:sched/urgent] sched_clock: Fix atomicity/continuity bug by using cmpxchg64() tip-bot for Eric Dumazet
2009-10-05 16:00             ` [PATCH] x86: Generate cmpxchg build failures Peter Zijlstra
2009-10-05 18:51               ` Maciej Żenczykowski
2009-10-05 19:16               ` Linus Torvalds
2009-10-05 19:33                 ` Peter Zijlstra
2009-10-05 20:54                   ` Linus Torvalds
2009-10-09 14:23                   ` [tip:x86/asm] " tip-bot for Peter Zijlstra
2009-09-28 14:34 ` Linux 2.6.32-rc1 compile error Wolfgang Erig
2009-09-28 15:10   ` Jaswinder Singh Rajput
2009-09-28 15:32     ` Wolfgang Erig
2009-09-28 16:25 ` [PATCH] isdn: fix netjet/isdnhdlc build errors Randy Dunlap
2009-09-28 19:47   ` David Miller

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