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From: Simon Wright <simon@pushface.org>
Subject: Re: Ada.Execution_Time
Date: Tue, 28 Dec 2010 22:39:31 +0000
Date: 2010-12-28T22:39:31+00:00	[thread overview]
Message-ID: <m2wrmt7c9o.fsf@pushface.org> (raw)
In-Reply-To: lur4ubobla6x$.1w9ka8t02c6ah.dlg@40tude.net

"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:

> Yes, the TSC can be read any time, and, if I correctly remember, each
> reading will give a new value. PPC RT clock is also reliable.
>
> There could be certain issues for multi-core processors, you should
> take care that the task synchronizing the counter with UTC would not
> jump from core to core. Alternatively you should synchronize clocks of
> individual cores.

Using the TSC on a MacBook Pro gives very unreliable results (I rather
think the core you're using goes to sleep and you may or may not wake
up using the same core!). However, the system clock (Ada.Calendar) is
precise to a microsecond.



  reply	other threads:[~2010-12-28 22:39 UTC|newest]

Thread overview: 124+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-12  4:19 Ada.Execution_Time BrianG
2010-12-12  5:27 ` Ada.Execution_Time Jeffrey Carter
2010-12-12 16:56 ` Ada.Execution_Time Jeffrey Carter
2010-12-12 21:59   ` Ada.Execution_Time BrianG
2010-12-12 22:08     ` Ada.Execution_Time BrianG
2010-12-13  9:28     ` Ada.Execution_Time Georg Bauhaus
2010-12-13 22:25       ` Ada.Execution_Time Randy Brukardt
2010-12-13 22:42         ` Ada.Execution_Time J-P. Rosen
2010-12-14  3:31         ` Ada.Execution_Time Jeffrey Carter
2010-12-14 15:42           ` Ada.Execution_Time Robert A Duff
2010-12-14 16:17             ` Ada.Execution_Time Jeffrey Carter
2010-12-14 19:10             ` Ada.Execution_Time Warren
2010-12-14 20:36               ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-14 20:48                 ` Ada.Execution_Time Jeffrey Carter
2010-12-14  8:17         ` Ada.Execution_Time Vinzent Hoefler
2010-12-14 15:51           ` Ada.Execution_Time Adam Beneschan
2010-12-14 15:53           ` Ada.Execution_Time Robert A Duff
2010-12-14 17:17             ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-14 17:45               ` Ada.Execution_Time Robert A Duff
2010-12-14 18:23                 ` Ada.Execution_Time Adam Beneschan
2010-12-14 21:02                   ` Ada.Execution_Time Randy Brukardt
2010-12-15 22:52             ` Ada.Execution_Time Keith Thompson
2010-12-15 23:14               ` Ada.Execution_Time Adam Beneschan
2010-12-17  0:44                 ` Ada.Execution_Time Randy Brukardt
2010-12-17 17:54                   ` Ada.Execution_Time Warren
2010-12-20 21:28                   ` Ada.Execution_Time Keith Thompson
2010-12-21  3:23                     ` Ada.Execution_Time Robert A Duff
2010-12-21  8:04                       ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-21 17:19                         ` Ada.Execution_Time Robert A Duff
2010-12-21 17:43                           ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-14 19:43           ` Ada.Execution_Time anon
2010-12-14 20:09             ` Ada.Execution_Time Adam Beneschan
2010-12-15  0:16       ` Ada.Execution_Time BrianG
2010-12-15 19:17         ` Ada.Execution_Time jpwoodruff
2010-12-15 21:42           ` Ada.Execution_Time Pascal Obry
2010-12-16  3:54             ` Ada.Execution_Time jpwoodruff
2010-12-17  7:11               ` Ada.Execution_Time Stephen Leake
2010-12-15 21:40         ` Ada.Execution_Time Simon Wright
2010-12-15 23:40           ` Ada.Execution_Time BrianG
2010-12-15 22:05         ` Ada.Execution_Time Randy Brukardt
2010-12-16  1:14           ` Ada.Execution_Time BrianG
2010-12-16  5:46             ` Ada.Execution_Time Jeffrey Carter
2010-12-16 16:13               ` Ada.Execution_Time BrianG
2010-12-16 11:37             ` Ada.Execution_Time Simon Wright
2010-12-16 17:24               ` Ada.Execution_Time BrianG
2010-12-16 17:45                 ` Ada.Execution_Time Adam Beneschan
2010-12-16 21:13                   ` Ada.Execution_Time Jeffrey Carter
2010-12-17  0:35               ` New AdaIC site (was: Ada.Execution_Time) Randy Brukardt
2010-12-16 13:08             ` Ada.Execution_Time Peter C. Chapin
2010-12-16 17:32               ` Ada.Execution_Time BrianG
2010-12-16 18:17             ` Ada.Execution_Time Jeffrey Carter
2010-12-16  8:45           ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-16 16:49             ` Ada.Execution_Time BrianG
2010-12-16 17:52               ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-17  8:49                 ` Ada.Execution_Time Niklas Holsti
2010-12-17  9:32                   ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-17 11:50                     ` Ada.Execution_Time Niklas Holsti
2010-12-17 13:10                       ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-18 21:20                         ` Ada.Execution_Time Niklas Holsti
2010-12-19  9:57                           ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-25 11:31                             ` Ada.Execution_Time Niklas Holsti
2010-12-26 10:25                               ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-27 12:44                                 ` Ada.Execution_Time Niklas Holsti
2010-12-27 15:28                                   ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-27 20:11                                     ` Ada.Execution_Time Niklas Holsti
2010-12-27 21:34                                       ` Ada.Execution_Time Simon Wright
2010-12-28 10:01                                         ` Ada.Execution_Time Niklas Holsti
2010-12-28 14:17                                           ` Ada.Execution_Time Simon Wright
2010-12-27 21:53                                       ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-28 14:14                                         ` Ada.Execution_Time Simon Wright
2010-12-28 15:08                                           ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-28 16:18                                             ` Ada.Execution_Time Simon Wright
2010-12-28 16:34                                               ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-31  0:40                                             ` Ada.Execution_Time BrianG
2010-12-31  9:09                                               ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-28 14:46                                         ` Ada.Execution_Time Niklas Holsti
2010-12-28 15:42                                           ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-28 16:27                                             ` Ada.Execution_Time (see below)
2010-12-28 16:55                                               ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-28 19:41                                                 ` Ada.Execution_Time (see below)
2010-12-28 20:03                                                   ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-28 22:39                                                     ` Simon Wright [this message]
2010-12-29  9:07                                                       ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-27 17:24                                 ` Ada.Execution_Time Robert A Duff
2010-12-27 22:02                                   ` Ada.Execution_Time Randy Brukardt
2010-12-27 22:43                                     ` Ada.Execution_Time Robert A Duff
2010-12-27 22:11                               ` Ada.Execution_Time Randy Brukardt
2010-12-29 12:48                                 ` Ada.Execution_Time Niklas Holsti
2010-12-29 14:30                                   ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-29 16:19                                     ` Ada.Execution_Time (see below)
2010-12-29 16:51                                       ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-29 19:57                                         ` Ada.Execution_Time (see below)
2010-12-29 21:20                                           ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-30  5:13                                             ` Ada.Execution_Time Randy Brukardt
2010-12-30 13:37                                             ` Ada.Execution_Time Niklas Holsti
2010-12-29 20:32                                     ` Ada.Execution_Time Niklas Holsti
2010-12-29 21:21                                       ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-30 13:34                                         ` Ada.Execution_Time Niklas Holsti
2010-12-30 19:23                                     ` Ada.Execution_Time Niklas Holsti
2010-12-30  5:06                                   ` Ada.Execution_Time Randy Brukardt
2010-12-30 23:49                                     ` Ada.Execution_Time Niklas Holsti
2010-12-31 23:34                                       ` Ada.Execution_Time Randy Brukardt
2011-01-01 13:52                                         ` Ada.Execution_Time Niklas Holsti
2011-01-01 14:42                                           ` Ada.Execution_Time Simon Wright
2011-01-01 16:01                                             ` Ada.Execution_Time Simon Wright
2011-01-01 19:18                                               ` Ada.Execution_Time Niklas Holsti
2011-01-03 21:27                                           ` Ada.Execution_Time Randy Brukardt
2011-01-06 22:55                                             ` Ada.Execution_Time Niklas Holsti
2011-01-07  6:25                                               ` Ada.Execution_Time Randy Brukardt
2011-01-01 15:54                                         ` Ada.Execution_Time Simon Wright
2011-01-03 21:33                                           ` Ada.Execution_Time Randy Brukardt
2011-01-05 15:55                                             ` Ada.Execution_Time Brad Moore
2010-12-17  8:59         ` Ada.Execution_Time anon
2010-12-19  3:07           ` Ada.Execution_Time BrianG
2010-12-19  4:01             ` Ada.Execution_Time Vinzent Hoefler
2010-12-19 11:00               ` Ada.Execution_Time Niklas Holsti
2010-12-21  0:37                 ` Ada.Execution_Time Randy Brukardt
2010-12-21  1:20                   ` Ada.Execution_Time Jeffrey Carter
2010-12-19 12:27               ` Ada.Execution_Time Dmitry A. Kazakov
2010-12-21  0:32               ` Ada.Execution_Time Randy Brukardt
2010-12-19 22:54             ` Ada.Execution_Time anon
2010-12-20  3:14               ` Ada.Execution_Time BrianG
2010-12-22 14:30                 ` Ada.Execution_Time anon
2010-12-22 20:09                   ` Ada.Execution_Time BrianG
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