From: Helge Hafting <helge.hafting@aitel.hist.no>
To: davids@webmaster.com
Cc: hyc@symas.com, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: pthread_mutex_unlock (was Re: sched_yield() makes OpenLDAP slow)
Date: Mon, 30 Jan 2006 09:28:38 +0100 [thread overview]
Message-ID: <43DDCE36.9020902@aitel.hist.no> (raw)
In-Reply-To: <MDEHLPKNGKAHNMBLJOLKGENPJKAB.davids@webmaster.com>
David Schwartz wrote:
> Third, there's the ambiguity of the standard. It says the "sceduling
>policy" shall decide, not that the scheduler shall decide. If the policy is
>to make a conditional or delayed decision, that is still perfectly valid
>policy. "Whichever thread requests it first" is a valid scheduler policy.
>
>
Sure. And with a "whichever thread aquires it first" policy, then
it is obvious what happens when a mutex is released when someone
is blocked on it: Whoever blocked on it first is then the one
who requested it first - that cannot change as the request was made
before the mutex even was released. So then, the releasing thread has
no chance of getting the mutex back until the others have had a
go at it - no matter what threads actually gets scheduled.
Helge Hafting
next prev parent reply other threads:[~2006-01-30 8:23 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-24 22:59 e100 oops on resume Stefan Seyfried
2006-01-24 23:21 ` Mattia Dongili
2006-01-25 9:02 ` Olaf Kirch
2006-01-25 12:11 ` Olaf Kirch
2006-01-25 13:51 ` sched_yield() makes OpenLDAP slow Howard Chu
2006-01-25 14:38 ` Robert Hancock
2006-01-25 17:49 ` Christopher Friesen
2006-01-25 18:26 ` pthread_mutex_unlock (was Re: sched_yield() makes OpenLDAP slow) Howard Chu
2006-01-25 18:59 ` Nick Piggin
2006-01-25 19:32 ` Howard Chu
2006-01-26 8:51 ` Nick Piggin
2006-01-26 14:15 ` Kyle Moffett
2006-01-26 14:43 ` Howard Chu
2006-01-26 19:57 ` David Schwartz
2006-01-26 20:27 ` Howard Chu
2006-01-26 20:46 ` Nick Piggin
2006-01-26 21:32 ` Howard Chu
2006-01-26 21:41 ` Nick Piggin
2006-01-26 21:56 ` Howard Chu
2006-01-26 22:24 ` Nick Piggin
2006-01-27 8:08 ` Howard Chu
2006-01-27 19:25 ` Philipp Matthias Hahn
2006-02-01 12:31 ` Nick Piggin
2006-01-27 4:27 ` Steven Rostedt
2006-01-26 21:58 ` Christopher Friesen
2006-01-27 4:13 ` Steven Rostedt
2006-01-27 2:16 ` David Schwartz
2006-01-27 8:19 ` Howard Chu
2006-01-27 19:50 ` David Schwartz
2006-01-27 20:13 ` Howard Chu
2006-01-27 21:05 ` David Schwartz
2006-01-27 21:23 ` Howard Chu
2006-01-27 23:31 ` David Schwartz
2006-01-30 8:28 ` Helge Hafting [this message]
2006-01-26 10:38 ` Nikita Danilov
2006-01-30 8:35 ` Helge Hafting
2006-01-30 11:13 ` Nikita Danilov
2006-01-31 23:18 ` David Schwartz
2006-01-25 21:06 ` Lee Revell
2006-01-25 22:14 ` Howard Chu
2006-01-26 0:16 ` Robert Hancock
2006-01-26 0:49 ` Howard Chu
2006-01-26 1:04 ` Lee Revell
2006-01-26 1:31 ` Howard Chu
2006-01-26 2:05 ` David Schwartz
2006-01-26 2:48 ` Mark Lord
2006-01-26 3:30 ` David Schwartz
2006-01-26 3:49 ` Samuel Masham
2006-01-26 4:02 ` Samuel Masham
2006-01-26 4:53 ` Lee Revell
2006-01-26 6:14 ` Samuel Masham
2006-01-26 8:54 ` Nick Piggin
2006-01-26 14:24 ` Howard Chu
2006-01-26 14:54 ` Nick Piggin
2006-01-26 15:23 ` Howard Chu
2006-01-26 15:51 ` Nick Piggin
2006-01-26 16:44 ` Howard Chu
2006-01-26 17:34 ` linux-os (Dick Johnson)
2006-01-26 19:00 ` Nick Piggin
2006-01-26 19:14 ` linux-os (Dick Johnson)
2006-01-26 21:12 ` Nick Piggin
2006-01-26 21:31 ` linux-os (Dick Johnson)
2006-01-27 7:06 ` Valdis.Kletnieks
2006-01-30 8:44 ` Helge Hafting
2006-01-30 8:50 ` Howard Chu
2006-01-30 15:33 ` Kyle Moffett
2006-01-30 13:28 ` linux-os (Dick Johnson)
2006-01-30 15:15 ` Helge Hafting
2006-01-26 10:44 ` Nikita Danilov
2006-01-26 0:08 ` Robert Hancock
2006-01-26 1:07 ` sched_yield() makes OpenLDAP slow David Schwartz
2006-01-26 8:30 ` Helge Hafting
2006-01-26 9:01 ` Nick Piggin
2006-01-26 10:50 ` Nikita Danilov
2006-01-25 19:37 ` e100 oops on resume Jesse Brandeburg
2006-01-25 20:14 ` Olaf Kirch
2006-01-25 22:28 ` Jesse Brandeburg
2006-01-26 0:28 ` Jesse Brandeburg
2006-01-26 9:32 ` Pavel Machek
2006-01-26 19:02 ` Stefan Seyfried
2006-01-26 19:09 ` Olaf Kirch
2006-01-28 11:53 ` Mattia Dongili
2006-01-28 19:53 ` Jesse Brandeburg
2006-02-07 6:57 ` Jeff Garzik
[not found] ` <BAY108-DAV111F6EF46F6682FEECCC1593140@phx.gbl>
[not found] ` <4807377b0601271404w6dbfcff6s4de1c3f785dded9f@mail.gmail.com>
2006-01-30 17:25 ` Can I do a regular read to simulate prefetch instruction? John Smith
-- strict thread matches above, loose matches on Subject: below --
2006-01-30 22:01 pthread_mutex_unlock (was Re: sched_yield() makes OpenLDAP slow) linux
2006-01-30 23:37 linux
2006-02-01 17:06 Lee Schermerhorn
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