Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268955AbUJTSH4 (ORCPT ); Wed, 20 Oct 2004 14:07:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268919AbUJTSHp (ORCPT ); Wed, 20 Oct 2004 14:07:45 -0400 Received: from viper.oldcity.dca.net ([216.158.38.4]:36253 "HELO viper.oldcity.dca.net") by vger.kernel.org with SMTP id S268728AbUJTRzi (ORCPT ); Wed, 20 Oct 2004 13:55:38 -0400 Subject: Re: [PATCH 1/3] Separate IRQ-stacks from 4K-stacks option From: Lee Revell To: Timothy Miller Cc: Arjan van de Ven , Andrea Arcangeli , Hugh Dickins , "Martin J. Bligh" , Andrea Arcangeli , Alan Cox , Chris Wedgwood , LKML , Christoph Hellwig In-Reply-To: <4176A749.8050306@techsource.com> References: <593560000.1094826651@[10.10.2.4]> <20040910151538.GA24434@devserv.devel.redhat.com> <20040910152852.GC15643@x30.random> <20040910153421.GD24434@devserv.devel.redhat.com> <41768858.8070709@techsource.com> <20041020153521.GB21556@devserv.devel.redhat.com> <1098290345.1429.65.camel@krustophenia.net> <4176A749.8050306@techsource.com> Content-Type: text/plain Message-Id: <1098294932.1429.153.camel@krustophenia.net> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Wed, 20 Oct 2004 13:55:33 -0400 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1482 Lines: 46 On Wed, 2004-10-20 at 13:58, Timothy Miller wrote: > Lee Revell wrote: > > On Wed, 2004-10-20 at 11:35, Arjan van de Ven wrote: > > > >>On Wed, Oct 20, 2004 at 11:46:32AM -0400, Timothy Miller wrote: > >> > >>>The rules about how long a hard irq would be allowed to run would have > >>>to be draconian. > >> > >>they already are. > > > > > > The IDE I/O completion in hardirq context means that one can run for > > almost 3ms. Apparently at OLS it was decided that the target for > > desktop responsiveness was 1ms. So this is a real problem. > > What is happening that takes 3ms, and why can't it be broken up? > http://lkml.org/lkml/2004/7/24/26 > Are you talking here about PIO? Is there a limited amount of time you > have to do the PIO before the data goes away? It may be acceptable to > just live with PIO being slow, since high-performance systems will all > be using DMA anyhow. > Nope, DMA. > > > > What exactly do you mean by "draconian"? > > In this case, I mean extremely harsh and restrictive. Usually, it means > "excessively harsh", but in this case, I mean that in a good way. :) > Heh, I know what the word means, I was asking what the specific rules are that could be considered as such. Lee - 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/