From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756403AbYKUPgU (ORCPT ); Fri, 21 Nov 2008 10:36:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754613AbYKUPgF (ORCPT ); Fri, 21 Nov 2008 10:36:05 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:39305 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751909AbYKUPgC (ORCPT ); Fri, 21 Nov 2008 10:36:02 -0500 Date: Fri, 21 Nov 2008 16:34:53 +0100 From: Ingo Molnar To: Eric Dumazet Cc: David Miller , cl@linux-foundation.org, rjw@sisk.pl, linux-kernel@vger.kernel.org, kernel-testers@vger.kernel.org, efault@gmx.de, a.p.zijlstra@chello.nl, Linux Netdev List Subject: Re: [PATCH] fs: pipe/sockets/anon dentries should not have a parent Message-ID: <20081121153453.GA23713@elte.hu> References: <20081121083044.GL16242@elte.hu> <49267694.1030506@cosmosbay.com> <20081121.010508.40225532.davem@davemloft.net> <4926AEDB.10007@cosmosbay.com> <4926D022.5060008@cosmosbay.com> <20081121152148.GA20388@elte.hu> <4926D39D.9050603@cosmosbay.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4926D39D.9050603@cosmosbay.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Eric Dumazet wrote: > Ingo Molnar a écrit : >> * Eric Dumazet wrote: >> >>> Before patch, time to run 8 millions of close(socket()) calls on 8 >>> CPUS was : >>> >>> real 0m27.496s >>> user 0m0.657s >>> sys 3m39.092s >>> >>> After patch : >>> >>> real 0m23.997s >>> user 0m0.682s >>> sys 3m11.193s >> >> cool :-) >> >> What would it take to get it down to: >> >>>> Cost if run one one cpu : >>>> >>>> real 0m1.561s >>>> user 0m0.092s >>>> sys 0m1.469s >> >> i guess asking for a wall-clock cost of 1.561/8 would be too much? :) >> > > It might be possible, depending on the level of hackery I am allowed > to inject in fs/dcache.c and fs/inode.c :) I think being able to open+close sockets in a scalable way is an undisputed prime-time workload on Linux. The numbers you showed look horrible. Once you can show how much faster it could go via hacks, it should only be a matter of time to achieve that safely and cleanly. > wall cost of 1.56 (each cpu runs one loop of one million iterations) (indeed.) Ingo