Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754131AbbHJO3A (ORCPT ); Mon, 10 Aug 2015 10:29:00 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:57331 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751911AbbHJO26 (ORCPT ); Mon, 10 Aug 2015 10:28:58 -0400 Date: Mon, 10 Aug 2015 16:28:47 +0200 From: Peter Zijlstra To: Frederic Weisbecker Cc: Juri Lelli , LKML , Thomas Gleixner , Preeti U Murthy , Christoph Lameter , Ingo Molnar , Viresh Kumar , Rik van Riel Subject: Re: [PATCH 07/10] sched: Migrate sched to use new tick dependency mask model Message-ID: <20150810142847.GE16853@twins.programming.kicks-ass.net> References: <1437669735-8786-1-git-send-email-fweisbec@gmail.com> <1437669735-8786-8-git-send-email-fweisbec@gmail.com> <20150803140046.GK19282@twins.programming.kicks-ass.net> <20150803145031.GD25554@lerouge> <20150803170911.GV25159@twins.programming.kicks-ass.net> <20150803173031.GB26022@lerouge> <20150804074116.GH25159@twins.programming.kicks-ass.net> <55C8AEDC.90603@arm.com> <20150810141656.GA31251@lerouge> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150810141656.GA31251@lerouge> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 824 Lines: 17 On Mon, Aug 10, 2015 at 04:16:58PM +0200, Frederic Weisbecker wrote: > I considered many times relying on hrtick btw but everyone seem to say it has a lot > of overhead, especially due to clock reprogramming on schedule() calls. Yeah, I have some vague ideas of how to take out much of that overhead (tglx will launch frozen sharks at me I suspect), but we cannot get around the overhead of actually having to program the hardware and that is still a significant amount on many machines. Supposedly machines with TSC deadline are better, but I've not tried to benchmark that. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/