Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267411AbUIHNFf (ORCPT ); Wed, 8 Sep 2004 09:05:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267372AbUIHNCJ (ORCPT ); Wed, 8 Sep 2004 09:02:09 -0400 Received: from mx2.elte.hu ([157.181.151.9]:33772 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S267238AbUIHNAH (ORCPT ); Wed, 8 Sep 2004 09:00:07 -0400 Date: Wed, 8 Sep 2004 15:01:36 +0200 From: Ingo Molnar To: Zwane Mwaikambo Cc: Andrew Morton , Linux Kernel Subject: Re: [patch] preempt-smp.patch, 2.6.9-rc1-bk14 Message-ID: <20040908130136.GB20132@elte.hu> References: <20040908111751.GA11507@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1173 Lines: 27 * Zwane Mwaikambo wrote: > > In addition to the preemption latency problems, the _irq() variants in > > the above list didnt do any IRQ-enabling while spinning - possibly > > resulting in excessive irqs-off sections of code! > > I had a patch for this > http://www.ussg.iu.edu/hypermail/linux/kernel/0405.3/0578.html and it > has been running for about 3 months now on a heavily used 4 processor > box. It's all a matter of whether Andrew is feeling brave ;) at a quick glance your patch doesnt seem to cover the following locking primitives: read_lock_irqsave(), read_lock_irq(), write_lock_irqsave, write_lock_irq(). Also, i think your 2.6.6 patch doesnt apply anymore because it clashes with your very nice out-of-line spinlocks patch that went into -BK recently ;) anyway, the preempt-smp.patch is a complete and systematic solution that has been tested, measured and traced quite heavily. Ingo - 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/