From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750920AbWB0KLH (ORCPT ); Mon, 27 Feb 2006 05:11:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750985AbWB0KLH (ORCPT ); Mon, 27 Feb 2006 05:11:07 -0500 Received: from smtp109.mail.mud.yahoo.com ([209.191.85.219]:41101 "HELO smtp109.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S1750920AbWB0KLG (ORCPT ); Mon, 27 Feb 2006 05:11:06 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=5qnVP+Vh4bGodOWFRrn3b6bXiS5zGJg6W0btwFATJRi+GCktjC38FUMmj3WphnMk+bCkZ0hPylghAimKjB79hzbMx+ew4NyM2NVbST1VMF1qPlIJbvW/D3/GLD+tcSEwMFDM9DhiqXbcbHUxG0haP/CWc3iQU+0JMmSG71i4mII= ; Message-ID: <4402D039.1050307@yahoo.com.au> Date: Mon, 27 Feb 2006 21:11:05 +1100 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: john@johnmccutchan.com CC: Andrew Morton , holt@sgi.com, linux-kernel@vger.kernel.org, rml@novell.com, arnd@arndb.de, hch@lst.de, Dipankar Sarma Subject: Re: udevd is killing file write performance. References: <20060222134250.GE20786@lnx-holt.americas.sgi.com> <1140626903.13461.5.camel@localhost.localdomain> <20060222175030.GB30556@lnx-holt.americas.sgi.com> <1140648776.1729.5.camel@localhost.localdomain> <20060222151223.5c9061fd.akpm@osdl.org> <1140651662.2985.2.camel@localhost.localdomain> <20060223161425.4388540e.akpm@osdl.org> <20060224054724.GA8593@johnmccutchan.com> <20060223220053.2f7a977e.akpm@osdl.org> <43FEB0BF.6080403@yahoo.com.au> <1140972918.15634.1.camel@localhost.localdomain> In-Reply-To: <1140972918.15634.1.camel@localhost.localdomain> 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 John McCutchan wrote: > On Fri, 2006-24-02 at 18:07 +1100, Nick Piggin wrote: >>I saw this problem when testing my lockless pagecache a while back. >> >>Attached is a first implementation of what was my idea then of how >>to solve it... note it is pretty rough and I never got around to doing >>much testing of it. >> >>Basically: moves work out of inotify event time and to inotify attach >>/detach time while staying out of the core VFS. > > > > This looks really good. There might be some corner cases but it looks > like it will solve this problem nicely. > Thanks. You should see I sent a new version which fixes several bugs and cleans up the code a bit. There might be some areas of potential problems: - creating and deleting watches on directories with many entries will take a long time. Is anyone likely to be creating and destroying these things at a very high frequency? Probably nobody cares except it might twist some real-time knickers. - concurrent operations in the same watched directory will incur the same scalability penalty. I think this is basically a non-issue since the sheer number of events coming out will likely be a bigger problem. Doctor, it hurts when I do this. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com