Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268914AbUJTRyw (ORCPT ); Wed, 20 Oct 2004 13:54:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268971AbUJTRy3 (ORCPT ); Wed, 20 Oct 2004 13:54:29 -0400 Received: from kinesis.swishmail.com ([209.10.110.86]:51465 "EHLO kinesis.swishmail.com") by vger.kernel.org with ESMTP id S268767AbUJTRrE (ORCPT ); Wed, 20 Oct 2004 13:47:04 -0400 Message-ID: <4176A749.8050306@techsource.com> Date: Wed, 20 Oct 2004 13:58:33 -0400 From: Timothy Miller MIME-Version: 1.0 To: Lee Revell CC: Arjan van de Ven , Andrea Arcangeli , Hugh Dickins , "Martin J. Bligh" , Andrea Arcangeli , Alan Cox , Chris Wedgwood , LKML , Christoph Hellwig Subject: Re: [PATCH 1/3] Separate IRQ-stacks from 4K-stacks option 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> In-Reply-To: <1098290345.1429.65.camel@krustophenia.net> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1213 Lines: 35 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? 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. > > 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. :) - 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/