Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756568Ab0FQLYh (ORCPT ); Thu, 17 Jun 2010 07:24:37 -0400 Received: from hera.kernel.org ([140.211.167.34]:35732 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750701Ab0FQLYg (ORCPT ); Thu, 17 Jun 2010 07:24:36 -0400 Message-ID: <4C1A05AF.5010405@kernel.org> Date: Thu, 17 Jun 2010 13:23:27 +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: Thomas Gleixner CC: 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> In-Reply-To: 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 11:23:29 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 993 Lines: 24 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 and if we get running avg w/ fairly large stability part, the numbers wouldn't be too far off and there's no reliable way for the driver to tell which type of device is on the other side of the cable. So, I think running avg would work much better. 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/