Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268686AbUJTQvj (ORCPT ); Wed, 20 Oct 2004 12:51:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268655AbUJTQv2 (ORCPT ); Wed, 20 Oct 2004 12:51:28 -0400 Received: from mail-relay-1.tiscali.it ([213.205.33.41]:42889 "EHLO mail-relay-1.tiscali.it") by vger.kernel.org with ESMTP id S268686AbUJTQuM (ORCPT ); Wed, 20 Oct 2004 12:50:12 -0400 Date: Wed, 20 Oct 2004 18:50:50 +0200 From: Andrea Arcangeli To: Lee Revell Cc: Arjan van de Ven , Timothy Miller , 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 Message-ID: <20041020165050.GA24619@dualathlon.random> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1098290345.1429.65.camel@krustophenia.net> X-GPG-Key: 1024D/68B9CB43 13D9 8355 295F 4823 7C49 C012 DFA1 686E 68B9 CB43 X-PGP-Key: 1024R/CB4660B9 CC A0 71 81 F4 A0 63 AC C0 4B 81 1D 8C 15 C8 E5 User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 822 Lines: 16 On Wed, Oct 20, 2004 at 12:39:06PM -0400, Lee Revell wrote: > 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. comparing netsted irqs to a context switch is a red herring. nested irqs statistically do good, with long irq handlers vs short irq handlers. The irq handlers that really know to be extremely quick aren't forced to re-enable irqs, so they can enforce no-nesting by themself. Enforcing it globally sounds bad to me. - 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/