From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752864Ab0H0HjL (ORCPT ); Fri, 27 Aug 2010 03:39:11 -0400 Received: from casper.infradead.org ([85.118.1.10]:54075 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752167Ab0H0HjJ convert rfc822-to-8bit (ORCPT ); Fri, 27 Aug 2010 03:39:09 -0400 Subject: Re: [RFC PATCH 00/11] sched: CFS low-latency features From: Peter Zijlstra To: Mathieu Desnoyers Cc: Thomas Gleixner , LKML , Linus Torvalds , Andrew Morton , Ingo Molnar , Steven Rostedt , Tony Lindgren , Mike Galbraith In-Reply-To: <20100826233651.GB28177@Krystal> References: <20100826180908.648103531@efficios.com> <1282849045.1975.1587.camel@laptop> <20100826230934.GA4194@Krystal> <20100826233651.GB28177@Krystal> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Fri, 27 Aug 2010 09:38:38 +0200 Message-ID: <1282894718.1975.1654.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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.