From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752972Ab0H0Hhx (ORCPT ); Fri, 27 Aug 2010 03:37:53 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:53734 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752859Ab0H0Hhu convert rfc822-to-8bit (ORCPT ); Fri, 27 Aug 2010 03:37:50 -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: <20100826230934.GA4194@Krystal> References: <20100826180908.648103531@efficios.com> <1282849045.1975.1587.camel@laptop> <20100826230934.GA4194@Krystal> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Fri, 27 Aug 2010 09:37:35 +0200 Message-ID: <1282894655.1975.1650.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 19:09 -0400, Mathieu Desnoyers wrote: > > WTF can't the damned delivery thread not be created when timer_create > > is called and the signal be delivered to that very thread directly via > > SIGEV_THREAD_ID ? > > Yeah, that sounds exactly like what I proposed about an hour ago on IRC ;) I'm > pretty sure that would work. > > 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. Simply don't use SIGEV_THREAD and spawn you own thread and use SIGEV_THREAD_ID yourself, the programmer knows the semantics and knows if he cares about overlapping timers etc.