Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263117AbUILWGX (ORCPT ); Sun, 12 Sep 2004 18:06:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263003AbUILWGU (ORCPT ); Sun, 12 Sep 2004 18:06:20 -0400 Received: from mail-relay-2.tiscali.it ([213.205.33.42]:41186 "EHLO mail-relay-2.tiscali.it") by vger.kernel.org with ESMTP id S263117AbUILWGP (ORCPT ); Sun, 12 Sep 2004 18:06:15 -0400 Date: Mon, 13 Sep 2004 00:07:20 +0200 From: Andrea Arcangeli To: Lee Revell Cc: Ingo Molnar , Chris Wedgwood , Arjan van de Ven , Hugh Dickins , "Martin J. Bligh" , Alan Cox , LKML , Christoph Hellwig Subject: Re: [PATCH 1/3] Separate IRQ-stacks from 4K-stacks option Message-ID: <20040912220720.GC3049@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> <1095016687.1306.667.camel@krustophenia.net> <20040912192515.GA8165@taniwha.stupidest.org> <20040912193542.GB28791@elte.hu> <20040912203308.GA3049@dualathlon.random> <1095025000.22893.52.camel@krustophenia.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1095025000.22893.52.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: 752 Lines: 14 On Sun, Sep 12, 2004 at 05:36:41PM -0400, Lee Revell wrote: > But in this case the hardirq handler can run for 2ms, which caused a > scheduler latency problem, because nothing could run but other IRQs. > The IRQ threading in Ingo's patches solves the problem, and seems to me > to be the correct solution. the irq threading must have a cost, doesn't it? I doubt you want to offload irqs to a kernel thread on a server, *that* would be slow (irq nesting is zerocost compared to scheduling a kernel thread). - 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/