Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760277Ab0FQPzc (ORCPT ); Thu, 17 Jun 2010 11:55:32 -0400 Received: from hera.kernel.org ([140.211.167.34]:36788 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756264Ab0FQPz3 (ORCPT ); Thu, 17 Jun 2010 11:55:29 -0400 Message-ID: <4C1A4548.3020602@kernel.org> Date: Thu, 17 Jun 2010 17:54:48 +0200 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.1.9) Gecko/20100317 Thunderbird/3.0.4 MIME-Version: 1.0 To: Alan Cox CC: Thomas Gleixner , Arjan van de Ven , 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 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> In-Reply-To: <20100617124343.5889067c@lxorguk.ukuu.org.uk> X-Enigmail-Version: 1.0.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Thu, 17 Jun 2010 15:54:50 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1128 Lines: 31 On 06/17/2010 01:43 PM, Alan Cox wrote: > On Thu, 17 Jun 2010 13:23:27 +0200 > Tejun Heo wrote: > >> On 06/17/2010 01:12 PM, Thomas Gleixner wrote: >>>> Hmmm.... oh, I see. Wouldn't it be much better to use moving avg of >>>> IRQ durations instead of letting the driver specify it? Drivers are >>>> most likely to just hard code it and It's never gonna be accurate. >>> >>> Right, but that's probably more accurate than the core code heuristics >>> ever will be. >> >> Eh, not really. For ATA at least, there will be three different >> classes of devices. SSDs, hard drives and optical devices > > At least four: It may also be battery backed RAM. Yeah, right, there are those crazy devices too but I think they would fall in a single tick any way. At any rate, let's say I have those numbers, how would I feed it into c-state selection? Thanks. -- tejun -- 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/