Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759667Ab0FRJqe (ORCPT ); Fri, 18 Jun 2010 05:46:34 -0400 Received: from www.tglx.de ([62.245.132.106]:39635 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757353Ab0FRJqc (ORCPT ); Fri, 18 Jun 2010 05:46:32 -0400 Date: Fri, 18 Jun 2010 11:45:16 +0200 (CEST) From: Thomas Gleixner To: Tejun Heo cc: Arjan van de Ven , Alan Cox , mingo@elte.hu, bphilips@suse.de, yinghai@kernel.org, akpm@linux-foundation.org, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, jeff@garzik.org, linux-ide@vger.kernel.org, stern@rowland.harvard.edu, gregkh@suse.de, khali@linux-fr.org Subject: Re: [PATCH 09/12] irq: implement IRQ expecting In-Reply-To: <4C1B3B02.2040209@kernel.org> Message-ID: References: <1276443098-20653-1-git-send-email-tj@kernel.org> <1276443098-20653-10-git-send-email-tj@kernel.org> <20100616204854.4b036f87@infradead.org> <4C19DA64.8000409@kernel.org> <4C1A05AF.5010405@kernel.org> <20100617124343.5889067c@lxorguk.ukuu.org.uk> <4C1A4548.3020602@kernel.org> <20100617090229.543af62c@infradead.org> <4C1A5197.8060409@kernel.org> <20100617232649.6db5cc55@infradead.org> <4C1B3B02.2040209@kernel.org> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1653 Lines: 39 On Fri, 18 Jun 2010, Tejun Heo wrote: > Hello, > > On 06/18/2010 08:26 AM, Arjan van de Ven wrote: > > On Thu, 17 Jun 2010 18:47:19 +0200 > > Tejun Heo wrote: > > > >> > >> Hmmm... the thing is that there will be many cases which won't fit > >> irq_expect() model (why irq_watch() exists in the first place) and for > >> the time being libata is the only one providing that data. Would the > >> data still be useful to determine which c-state to use? > > > > yes absolutely. One of the hard cases right now that the C state code > > has is that it needs to predict the future. While it has a ton of > > heuristics, including some is there IO oustanding" ones, libata is a > > really good case: libata will know generally that within one seek time > > (5 msec on rotating rust, much less on floating electrons) there'll be > > an interrupt (give or take, but this is what we can do heuristics for > > on a per irq level). > > So it's a good suggestion of what the future will be like, MUCH better > > than any hint we have right now... all we have right now is some > > history, and when the next timer is.... > > Cool, good to know. It shouldn't be difficult to at all to add. Once > the whole thing gets generally agreed on, I'll work on that. > > Thomas, Ingo, through which tree should these patches routed through? I'm going to pull that into tip/genirq I guess Thanks, tglx -- 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/