From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@elte.hu>, Steven Rostedt <rostedt@goodmis.org>,
Tony Lindgren <tony@atomide.com>, Mike Galbraith <efault@gmx.de>
Subject: Re: [RFC PATCH 00/11] sched: CFS low-latency features
Date: Fri, 27 Aug 2010 11:23:19 -0400 [thread overview]
Message-ID: <20100827152319.GC14926@Krystal> (raw)
In-Reply-To: <1282894718.1975.1654.camel@laptop>
* Peter Zijlstra (peterz@infradead.org) wrote:
> On Thu, 2010-08-26 at 19:36 -0400, Mathieu Desnoyers wrote:
> > > The only thing we might have to be careful about is what happens if the timer
> > > re-fires before the thread completes its execution. We might want to let the
> > > signal handler detect these overruns somehow.
> >
> > Hrm, thinking about it a little more, one of the "plus" sides of these
> > SIGEV_THREAD timers is that a single timer can fork threads that will run on
> > many cores on a multi-core system. If we go for preallocation of a single
> > thread, we lose that. Maybe we could think of a way to preallocate a thread pool
> > instead ?
>
> Why try and fix a broken thing, just let the app spawn threads and use
> SIGEV_THREAD_ID itself, it knows its requirements and can do what suits
> the situation best. No need to try and patch up braindead posix stuff.
As I dig through the code and learn more about the posix standard, my
understanding is that the _implementation_ is broken. The standard just leaves
enough rope for the implementation to either do the right thing or to hang
itself. Sadly glibc seems to have chosen the second option.
Mathieu
--
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com
next prev parent reply other threads:[~2010-08-27 15:23 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-26 18:09 [RFC PATCH 00/11] sched: CFS low-latency features Mathieu Desnoyers
2010-08-26 18:09 ` [RFC PATCH 01/11] sched: fix string comparison in features Mathieu Desnoyers
2010-08-26 18:09 ` [RFC PATCH 02/11] sched: debug spread check account for nr_running Mathieu Desnoyers
2010-08-26 18:09 ` [RFC PATCH 03/11] sched: FAIR_SLEEPERS feature Mathieu Desnoyers
2010-08-26 18:09 ` [RFC PATCH 04/11] sched: debug cleanup place entity Mathieu Desnoyers
2010-08-26 18:09 ` [RFC PATCH 05/11] sched buddy enable buddy logic starting at 2 running threads Mathieu Desnoyers
2010-08-26 18:09 ` [RFC PATCH 06/11] sched: dynamic min_vruntime Mathieu Desnoyers
2010-08-26 18:09 ` [RFC PATCH 07/11] sched rename struct task in_iowait field to sched_in_iowait Mathieu Desnoyers
2010-08-26 18:09 ` [RFC PATCH 08/11] sched input interactivity-driven next buddy Mathieu Desnoyers
2010-08-26 18:09 ` [RFC PATCH 09/11] sched: timer-driven " Mathieu Desnoyers
2010-08-27 18:02 ` [RFC PATCH 09/11] sched: timer-driven next buddy (update) Mathieu Desnoyers
2010-08-27 18:14 ` Thomas Gleixner
2010-08-26 18:09 ` [RFC PATCH 10/11] sched: fork expedited Mathieu Desnoyers
2010-08-26 18:09 ` [RFC PATCH 11/11] sched: fair sleepers for timer and interactive Mathieu Desnoyers
2010-08-26 18:57 ` [RFC PATCH 00/11] sched: CFS low-latency features Peter Zijlstra
2010-08-26 21:25 ` Thomas Gleixner
2010-08-26 22:22 ` Thomas Gleixner
2010-08-26 23:09 ` Mathieu Desnoyers
2010-08-26 23:36 ` Mathieu Desnoyers
2010-08-27 7:38 ` Peter Zijlstra
2010-08-27 15:23 ` Mathieu Desnoyers [this message]
2010-08-27 8:43 ` Thomas Gleixner
2010-08-27 15:50 ` Mathieu Desnoyers
2010-08-27 7:37 ` Peter Zijlstra
2010-08-27 15:21 ` Mathieu Desnoyers
2010-08-27 15:41 ` Peter Zijlstra
2010-08-27 16:09 ` Mathieu Desnoyers
2010-08-27 17:27 ` Peter Zijlstra
2010-08-27 18:32 ` Mathieu Desnoyers
2010-08-27 19:23 ` Peter Zijlstra
2010-08-27 19:57 ` Mathieu Desnoyers
2010-08-31 15:02 ` Mathieu Desnoyers
2010-08-26 23:18 ` Paul E. McKenney
2010-08-26 23:28 ` Mathieu Desnoyers
2010-08-26 23:38 ` Paul E. McKenney
2010-08-26 23:53 ` Mathieu Desnoyers
2010-08-27 0:09 ` Paul E. McKenney
2010-08-27 15:18 ` Mathieu Desnoyers
2010-08-27 15:20 ` Thomas Gleixner
2010-08-27 15:30 ` Mathieu Desnoyers
2010-08-27 15:41 ` Peter Zijlstra
2010-08-26 23:49 ` Mathieu Desnoyers
2010-08-27 7:42 ` Peter Zijlstra
2010-08-27 8:19 ` Mike Galbraith
2010-08-27 15:43 ` Mathieu Desnoyers
2010-08-27 18:38 ` Mathieu Desnoyers
2010-08-28 7:33 ` Mike Galbraith
2010-08-27 10:47 ` Indan Zupancic
2010-08-27 10:58 ` Peter Zijlstra
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100827152319.GC14926@Krystal \
--to=mathieu.desnoyers@efficios.com \
--cc=akpm@linux-foundation.org \
--cc=efault@gmx.de \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=tony@atomide.com \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox