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From: "H. Peter Anvin" <hpa@linux.intel.com>
To: Arjan van de Ven <arjan@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
	Hagen Paul Pfeifer <hagen@jauu.net>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Ingo Molnar <mingo@kernel.org>,
	linux-kernel@vger.kernel.org,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Arnaldo Carvalho de Melo <acme@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [GIT PULL] perf fixes
Date: Sat, 23 Jun 2012 11:25:42 -0700	[thread overview]
Message-ID: <4FE60A26.30109@linux.intel.com> (raw)
In-Reply-To: <4FE51325.8090408@linux.intel.com>

On 06/22/2012 05:51 PM, Arjan van de Ven wrote:
> 
> if it's truely an official nop, it will take decoder bandwidth obviously
> (which can decode 3 to 4 instructions per cycle, depending on the
> brand/model of CPU and the total size in bytes of these instructions).
> likewise, at the end of the out of order pipeline, NOPs may take a
> retirement slot (again 3 to 4 instructions per cycle)
> 
> icache is there as well, and if the NOP actually changes cpu flags (some
> of the less fortunate ones do) that can create a false data dependency.
> 

If it changes CPU flags it's most definitely not a NOP.

Either way, the 0F 1F ops are official, and listed in the SDM.

	-hpa


  parent reply	other threads:[~2012-06-23 18:25 UTC|newest]

Thread overview: 376+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-22 13:36 [GIT PULL] perf fixes Ingo Molnar
2012-06-22 18:07 ` Linus Torvalds
2012-06-22 18:38   ` Hagen Paul Pfeifer
2012-06-22 18:52     ` Linus Torvalds
2012-06-22 19:06       ` Hagen Paul Pfeifer
2012-06-22 19:54         ` Steven Rostedt
     [not found]           ` <86448d73-2e19-416f-8104-ce72aa5d76eb@email.android.com>
2012-06-22 23:18             ` Steven Rostedt
2012-06-23  0:51               ` Arjan van de Ven
2012-06-23  1:57                 ` Steven Rostedt
2012-06-23 18:25                 ` H. Peter Anvin [this message]
2012-06-22 18:50   ` Steven Rostedt
  -- strict thread matches above, loose matches on Subject: below --
2023-01-06 11:57 Ingo Molnar
2023-01-06 21:19 ` pr-tracker-bot
2022-10-02 10:56 Ingo Molnar
2022-10-02 16:47 ` Linus Torvalds
2022-10-03 10:55   ` Ingo Molnar
2022-10-02 17:20 ` pr-tracker-bot
2022-08-28 14:35 Ingo Molnar
2022-08-28 18:18 ` pr-tracker-bot
2022-08-06 19:10 Ingo Molnar
2022-08-07  0:50 ` pr-tracker-bot
2021-07-11 13:26 Ingo Molnar
2021-07-11 18:22 ` pr-tracker-bot
2021-06-12 12:48 Ingo Molnar
2021-06-12 19:09 ` pr-tracker-bot
2021-03-21 10:56 Ingo Molnar
2021-03-21 18:45 ` pr-tracker-bot
2020-08-15 11:21 Ingo Molnar
2020-08-16  1:55 ` pr-tracker-bot
2020-04-25  9:19 Ingo Molnar
2020-04-25 19:30 ` pr-tracker-bot
2020-03-24  9:19 Ingo Molnar
2020-03-24 17:15 ` pr-tracker-bot
2020-03-02  7:23 Ingo Molnar
2020-03-03 23:35 ` pr-tracker-bot
2020-02-15  8:53 Ingo Molnar
2020-02-15 21:25 ` pr-tracker-bot
2020-01-18 17:58 Ingo Molnar
2020-01-18 21:05 ` pr-tracker-bot
2019-12-21 16:16 Ingo Molnar
2019-12-21 18:55 ` pr-tracker-bot
2019-12-17 11:34 Ingo Molnar
2019-12-17 19:06 ` Linus Torvalds
2019-12-18  6:58   ` Ingo Molnar
2019-12-17 19:20 ` pr-tracker-bot
2019-12-01 22:15 Ingo Molnar
2019-12-02  4:40 ` pr-tracker-bot
2019-11-16 21:33 Ingo Molnar
2019-11-17  0:35 ` pr-tracker-bot
2019-11-01 17:48 Ingo Molnar
2019-11-01 18:48 ` Linus Torvalds
2019-11-01 20:30   ` Ingo Molnar
2019-11-01 21:01     ` Ingo Molnar
2019-11-01 22:15     ` Linus Torvalds
2019-11-01 19:10 ` pr-tracker-bot
2019-10-12 13:31 Ingo Molnar
2019-10-12 22:35 ` pr-tracker-bot
2019-07-14 12:01 Ingo Molnar
2019-07-14 18:45 ` pr-tracker-bot
2019-06-29  8:54 Ingo Molnar
2019-06-29 11:45 ` pr-tracker-bot
2019-06-02 17:39 Ingo Molnar
2019-06-02 18:15 ` pr-tracker-bot
2019-05-16 16:05 Ingo Molnar
2019-05-16 18:20 ` pr-tracker-bot
2019-05-05 12:47 Ingo Molnar
2019-05-05 22:10 ` pr-tracker-bot
2019-04-20  7:43 Ingo Molnar
2019-04-20 19:25 ` pr-tracker-bot
2019-04-12 13:06 Ingo Molnar
2019-04-13  4:05 ` pr-tracker-bot
2019-02-17 10:10 Ingo Molnar
2019-02-17 16:50 ` pr-tracker-bot
2019-02-10  9:01 Ingo Molnar
2019-02-10 18:30 ` pr-tracker-bot
2019-01-11  7:44 Ingo Molnar
2019-01-11 18:00 ` pr-tracker-bot
2018-11-30  6:25 Ingo Molnar
2018-11-30 21:00 ` pr-tracker-bot
2018-11-17 10:55 Ingo Molnar
2018-11-18 20:05 ` pr-tracker-bot
2018-10-20  8:10 Ingo Molnar
2018-10-20 13:28 ` Greg Kroah-Hartman
2018-10-11  9:12 Ingo Molnar
2018-10-11 12:32 ` Greg Kroah-Hartman
2018-10-11  8:59 Ingo Molnar
2018-10-05  9:42 Ingo Molnar
2018-10-05  9:55 ` Ingo Molnar
2018-10-05 23:30   ` Greg Kroah-Hartman
2018-09-15 13:11 Ingo Molnar
2018-07-30 17:53 Ingo Molnar
2018-07-13 19:59 Ingo Molnar
2018-06-30  8:44 Ingo Molnar
2018-06-04  9:04 Ingo Molnar
2018-03-31 10:40 Ingo Molnar
2018-03-25  8:53 Ingo Molnar
2018-02-06 21:29 Ingo Molnar
2017-12-06 22:17 Ingo Molnar
2017-11-26 12:40 Ingo Molnar
2017-11-05 14:40 Ingo Molnar
2017-11-09  8:13 ` Markus Trippelsdorf
2017-10-14 16:04 Ingo Molnar
2017-09-13 18:00 Ingo Molnar
2017-09-12 15:32 Ingo Molnar
2017-07-21 10:15 Ingo Molnar
2017-06-10  8:39 Ingo Molnar
2017-05-12  7:31 Ingo Molnar
2017-03-07 20:30 Ingo Molnar
2017-02-28  8:01 Ingo Molnar
2017-02-11 18:12 Ingo Molnar
2017-02-02 21:01 Ingo Molnar
2017-01-18  9:27 Ingo Molnar
2017-01-15  9:59 Ingo Molnar
2016-12-23 22:50 Ingo Molnar
2016-12-07 18:45 Ingo Molnar
2016-11-23  9:00 Ingo Molnar
2016-11-14  7:56 Ingo Molnar
2016-10-28 19:41 Ingo Molnar
2016-10-18 11:07 Ingo Molnar
2016-09-13 18:14 Ingo Molnar
2016-08-18 20:38 Ingo Molnar
2016-08-12 19:35 Ingo Molnar
2016-07-26 14:13 Ingo Molnar
2016-07-08 13:42 Ingo Molnar
2016-06-10 12:50 Ingo Molnar
2016-05-13 18:51 Ingo Molnar
2016-05-06 11:26 Ingo Molnar
2016-04-28 17:56 Ingo Molnar
2016-04-03 11:00 Ingo Molnar
2016-02-20 11:14 Ingo Molnar
2016-01-14 10:03 Ingo Molnar
2016-01-08 12:46 Ingo Molnar
2015-12-08  4:22 Ingo Molnar
2015-09-17  8:02 Ingo Molnar
2015-09-02 18:11 Ingo Molnar
2015-08-22 12:19 Ingo Molnar
2015-08-14  7:12 Ingo Molnar
2015-07-18  2:53 Ingo Molnar
2015-07-06 15:29 Ingo Molnar
2015-06-13 14:29 Ingo Molnar
2015-06-05  8:37 Ingo Molnar
2015-05-15  7:17 Ingo Molnar
2015-05-06 12:52 Ingo Molnar
2015-04-03 13:11 Ingo Molnar
2015-03-17 16:48 Ingo Molnar
2015-03-01 17:00 Ingo Molnar
2015-02-20 13:40 Ingo Molnar
2015-01-30 18:44 Ingo Molnar
2015-01-17 14:15 Ingo Molnar
2015-01-11  8:42 Ingo Molnar
2014-11-20  7:46 Ingo Molnar
2014-10-31 11:13 Ingo Molnar
2014-11-03  9:02 ` Paul Bolle
2014-11-03 10:04   ` Peter Zijlstra
2014-09-19 10:46 Ingo Molnar
2014-08-24 20:25 Ingo Molnar
2014-07-16 11:11 Ingo Molnar
2014-06-18 16:39 Ingo Molnar
2014-05-22  8:04 Ingo Molnar
2014-05-01  6:34 Ingo Molnar
2014-04-20  8:02 Ingo Molnar
2014-04-19 10:41 Ingo Molnar
2014-04-16 13:04 Ingo Molnar
2014-03-22  9:06 Ingo Molnar
2014-03-16 16:34 Ingo Molnar
2014-03-02  8:51 Ingo Molnar
2014-02-22 19:16 Ingo Molnar
2014-02-09  8:01 Ingo Molnar
2014-01-25  7:30 Ingo Molnar
2014-01-19 12:08 Ingo Molnar
2013-12-19 16:52 Ingo Molnar
2013-12-02 14:39 Ingo Molnar
2013-11-15 19:46 Ingo Molnar
2013-11-01  9:56 Ingo Molnar
2013-10-29 10:04 Ingo Molnar
2013-10-26 12:24 Ingo Molnar
2013-10-28  8:28 ` Markus Trippelsdorf
2013-10-28  9:02   ` ------------------------------ Markus Trippelsdorf
2013-10-28  9:34     ` Markus Trippelsdorf
2013-10-28 12:34       ` Arnaldo Carvalho de Melo
2013-10-28 12:42         ` Arnaldo Carvalho de Melo
2013-10-28 12:59           ` Markus Trippelsdorf
2013-10-29  9:50           ` Stephane Eranian
2013-10-29 10:06             ` Ingo Molnar
2013-10-29 12:47             ` Arnaldo Carvalho de Melo
2013-10-08 12:12 Ingo Molnar
2013-09-28 18:03 Ingo Molnar
2013-09-29 11:47 ` Markus Trippelsdorf
2013-09-29 21:33   ` Andi Kleen
2013-09-29 22:47     ` Markus Trippelsdorf
2013-09-30  6:27     ` Ingo Molnar
2013-09-30 18:54       ` Andi Kleen
2013-10-01  8:42         ` Ingo Molnar
2013-09-25 18:00 Ingo Molnar
2013-09-18 16:06 Ingo Molnar
2013-09-12 13:38 Ingo Molnar
2013-09-12 18:03 ` Linus Torvalds
2013-09-12 18:10   ` Linus Torvalds
2013-09-12 18:43     ` Arnaldo Carvalho de Melo
2013-09-12 19:12       ` Arnaldo Carvalho de Melo
2013-09-12 19:13         ` Linus Torvalds
2013-09-12 19:55       ` Ingo Molnar
2013-09-12 19:58       ` David Ahern
2013-09-12 20:02         ` Arnaldo Carvalho de Melo
2013-09-12 20:31           ` Ingo Molnar
2013-09-12 20:43             ` Ingo Molnar
2013-09-12 20:18         ` Ingo Molnar
2013-09-12 20:38           ` Arnaldo Carvalho de Melo
2013-09-12 20:46             ` Ingo Molnar
2013-09-12 21:09               ` David Ahern
2013-09-12 21:18                 ` Ingo Molnar
2013-09-12 22:10                   ` David Ahern
2013-09-13  5:09                     ` Ingo Molnar
2013-09-13  9:32                       ` Jean Pihet
2013-09-13  9:45                         ` Ingo Molnar
2013-09-13 17:15                           ` Jean Pihet
2013-09-12 18:51     ` Linus Torvalds
2013-09-12 20:33       ` Ingo Molnar
2013-09-12 20:38         ` Linus Torvalds
2013-09-12 20:49           ` Ingo Molnar
2013-09-12 20:52             ` Linus Torvalds
2013-09-12 21:01               ` Ingo Molnar
2013-09-12 20:10     ` Ingo Molnar
2013-08-13 16:51 Ingo Molnar
2013-07-10  8:52 Ingo Molnar
2013-06-26  8:52 Ingo Molnar
2013-06-20  8:58 Ingo Molnar
2013-05-05 10:10 Ingo Molnar
2013-04-21  8:16 Ingo Molnar
2013-04-14 15:20 Ingo Molnar
2013-03-21  9:56 Ingo Molnar
2013-03-11 14:28 Ingo Molnar
2013-02-26  7:02 Ingo Molnar
2013-03-14 20:32 ` Linus Torvalds
2013-03-14 21:06   ` Linus Torvalds
2013-03-14 22:09     ` Stephane Eranian
2013-03-14 22:17       ` Linus Torvalds
2013-03-14 22:19         ` Stephane Eranian
2013-03-14 22:42           ` Stephane Eranian
2013-03-14 22:53             ` Stephane Eranian
2013-03-14 23:11               ` Stephane Eranian
2013-03-15  0:24                 ` Stephane Eranian
2013-03-15  1:06                   ` Linus Torvalds
2013-03-15  8:01                     ` Stephane Eranian
2013-03-15 10:50                       ` Stephane Eranian
2013-02-04 18:20 Ingo Molnar
2012-12-01 11:11 Ingo Molnar
2012-10-26 14:44 Ingo Molnar
2012-10-23 11:02 Ingo Molnar
2012-10-20  0:56 Ingo Molnar
2012-09-21 19:08 Ingo Molnar
2012-09-13 14:39 Ingo Molnar
2012-08-23 10:59 Ingo Molnar
2012-08-20  9:08 Ingo Molnar
2012-08-21  7:59 ` Ingo Molnar
2012-08-05 17:43 Ingo Molnar
2012-08-03 16:40 Ingo Molnar
2012-07-14  7:51 Ingo Molnar
2012-06-15 18:48 Ingo Molnar
2012-06-08  9:20 Ingo Molnar
2012-05-30 15:39 Ingo Molnar
2012-05-17  8:19 Ingo Molnar
2012-04-27  6:32 Ingo Molnar
2012-04-16 17:48 Ingo Molnar
2012-04-14 10:54 Ingo Molnar
2012-04-03 22:40 Ingo Molnar
2012-03-13 16:56 Ingo Molnar
2012-03-05  9:27 Ingo Molnar
2012-03-02 10:47 Ingo Molnar
2012-02-10 12:45 Ingo Molnar
2012-02-02 10:00 Ingo Molnar
2012-01-26 18:11 Ingo Molnar
2011-12-29 21:02 Ingo Molnar
2011-12-09  6:16 Ingo Molnar
2011-12-05 19:13 Ingo Molnar
2011-11-07 18:49 Ingo Molnar
2011-11-07 19:00 ` Linus Torvalds
2011-11-07 19:50   ` Ingo Molnar
2011-08-22 17:00 Ingo Molnar
2011-08-11  8:17 Ingo Molnar
2011-07-07 18:11 Ingo Molnar
2011-06-19  8:44 Ingo Molnar
2011-06-13  9:53 Ingo Molnar
2011-06-08 13:46 Ingo Molnar
2011-05-28 16:34 Ingo Molnar
2011-05-24  2:41 Ingo Molnar
2011-05-23 13:41 Ingo Molnar
2011-05-23 22:10 ` Eric Dumazet
2011-05-23 22:19   ` Frederic Weisbecker
2011-05-23 22:22     ` Eric Dumazet
2011-05-20 17:18 Ingo Molnar
2011-05-17 22:07 Ingo Molnar
2011-05-07 18:20 Ingo Molnar
2011-04-29 18:17 Ingo Molnar
2011-04-22 13:42 Ingo Molnar
2011-04-19 15:56 Ingo Molnar
2011-04-16 10:03 Ingo Molnar
2011-04-07 17:48 Ingo Molnar
2011-04-02 10:25 Ingo Molnar
2011-03-25 13:11 Ingo Molnar
2011-03-10  7:53 Ingo Molnar
2011-02-28 17:34 Ingo Molnar
2011-02-22 16:03 Ingo Molnar
2011-02-15 16:58 Ingo Molnar
2011-02-06 11:27 Ingo Molnar
2011-02-03 15:47 Ingo Molnar
2011-01-24 13:34 Ingo Molnar
2011-01-24 19:48 ` Linus Torvalds
2011-01-24 20:07   ` Ingo Molnar
2011-01-24 20:11     ` Ingo Molnar
2011-01-24 20:17       ` Ingo Molnar
2011-01-24 20:17     ` Linus Torvalds
2011-01-24 20:27       ` Linus Torvalds
2011-01-24 20:38         ` Arnaldo Carvalho de Melo
2011-01-24 21:13           ` Linus Torvalds
2011-01-24 21:25           ` Ingo Molnar
2011-01-24 22:00             ` Arnaldo Carvalho de Melo
2011-01-25  0:16               ` Ingo Molnar
2011-01-24 20:37       ` Davidlohr Bueso
2011-01-24 20:14   ` Arnaldo Carvalho de Melo
2011-01-18 18:59 Ingo Molnar
2011-01-18  9:42 Ingo Molnar
2011-01-15 15:24 Ingo Molnar
2011-01-11 11:32 Ingo Molnar
2011-01-03 19:04 Ingo Molnar
2010-12-23 12:56 Ingo Molnar
2010-12-19 15:34 Ingo Molnar
2010-12-08  7:55 Ingo Molnar
2010-11-28 17:36 Ingo Molnar
2010-11-26 13:20 Ingo Molnar
2010-11-11 10:38 Ingo Molnar
2010-10-30 18:21 Ingo Molnar
2010-10-13 15:21 Ingo Molnar
2010-10-05 14:49 Ingo Molnar
2010-09-26  8:38 Ingo Molnar
2010-09-21 19:39 Ingo Molnar
2010-09-10 14:26 Ingo Molnar
2010-08-25 17:44 Ingo Molnar
2010-08-24 19:06 Ingo Molnar
2010-08-19 14:55 Ingo Molnar
2010-08-18  8:14 Ingo Molnar
2010-07-23 19:41 Ingo Molnar
2010-07-16 17:30 Ingo Molnar
2010-07-08  4:36 Frederic Weisbecker
2010-07-08  4:40 ` Frederic Weisbecker
2010-07-08  6:36 ` Ingo Molnar
2010-07-04 20:24 Ingo Molnar
2010-06-10 10:25 Ingo Molnar
2010-06-02 12:28 Ingo Molnar
2010-05-31 23:02 Frederic Weisbecker
2010-06-01  6:59 ` Ingo Molnar
2010-05-30 19:27 Ingo Molnar
2010-05-20  9:44 Frederic Weisbecker
2010-05-20 12:40 ` Ingo Molnar
2010-05-11 19:18 Ingo Molnar
2010-05-12  0:39 ` Linus Torvalds
2010-04-06 17:49 Ingo Molnar
2010-04-04 10:15 Ingo Molnar
2010-04-03 10:47 Frederic Weisbecker
2010-03-28  5:11 Frederic Weisbecker
2010-03-29  3:33 ` Ingo Molnar
2010-03-26 15:16 Ingo Molnar
2010-03-16 16:06 Ingo Molnar
2010-03-11 19:12 Ingo Molnar
2010-02-22 16:50 Ingo Molnar
2010-02-22 17:01 ` Linus Torvalds
2010-02-22 17:15   ` Frederic Weisbecker
2010-02-14  9:06 Ingo Molnar
2010-01-31 17:32 Ingo Molnar
2010-01-21 15:38 Ingo Molnar
2009-12-31 12:00 Ingo Molnar
2009-12-18 18:59 Ingo Molnar
2009-09-22  7:51 Ingo Molnar
2009-09-22 14:49 ` Linus Torvalds
2009-09-22 14:59   ` Ingo Molnar
2009-09-22 15:13     ` Linus Torvalds

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