From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161274AbWAMHrr (ORCPT ); Fri, 13 Jan 2006 02:47:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161253AbWAMHrr (ORCPT ); Fri, 13 Jan 2006 02:47:47 -0500 Received: from smtp.osdl.org ([65.172.181.4]:57787 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1161284AbWAMHrq (ORCPT ); Fri, 13 Jan 2006 02:47:46 -0500 Date: Thu, 12 Jan 2006 23:47:26 -0800 From: Andrew Morton To: Nick Piggin Cc: hugh@veritas.com, andrea@suse.de, linux-kernel@vger.kernel.org Subject: Re: smp race fix between invalidate_inode_pages* and do_no_page Message-Id: <20060112234726.676c3873.akpm@osdl.org> In-Reply-To: <43C75834.3040007@yahoo.com.au> References: <20051213193735.GE3092@opteron.random> <20051213130227.2efac51e.akpm@osdl.org> <20051213211441.GH3092@opteron.random> <20051216135147.GV5270@opteron.random> <20060110062425.GA15897@opteron.random> <43C484BF.2030602@yahoo.com.au> <20060111082359.GV15897@opteron.random> <20060111005134.3306b69a.akpm@osdl.org> <20060111090225.GY15897@opteron.random> <20060111010638.0eb0f783.akpm@osdl.org> <20060111091327.GZ15897@opteron.random> <43C75834.3040007@yahoo.com.au> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Nick Piggin wrote: > > (I guess reclaim might be one, but quite rare -- any other significant > lock_page users that we might hit?) The only time 2.6 holds lock_page() for a significant duration is when bringing the page uptodate with readpage or memset. The scalability risk here is 100 CPUs all faulting in the same file in the same pattern. Like the workload which caused the page_table_lock splitup (that was with anon pages). All the CPUs could pretty easily get into sync and start arguing over every single page's lock.