From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261699AbTJMMUj (ORCPT ); Mon, 13 Oct 2003 08:20:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261705AbTJMMUj (ORCPT ); Mon, 13 Oct 2003 08:20:39 -0400 Received: from asplinux.ru ([195.133.213.194]:63752 "EHLO relay.asplinux.ru") by vger.kernel.org with ESMTP id S261699AbTJMMUh (ORCPT ); Mon, 13 Oct 2003 08:20:37 -0400 From: Kirill Korotaev Reply-To: kk@sw.ru Organization: SWsoft To: William Lee Irwin III Subject: Re: [PATCH] Invalidate_inodes can be very slow Date: Mon, 13 Oct 2003 16:21:33 +0400 User-Agent: KMail/1.5.1 References: <200310131318.09234.kk@sw.ru> <200310131602.20479.kk@sw.ru> <20031013121109.GJ16158@holomorphy.com> In-Reply-To: <20031013121109.GJ16158@holomorphy.com> Cc: Andrew Morton , linux-kernel@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200310131621.33079.kk@sw.ru> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > At some point in the past, I wrote: > >> Sorry if I was unclear, I had in mind SMP performance testing of mount > >> and unmount -heavy workloads, like uni setups with many automounted > >> fs's, not stability testing per se. > > On Mon, Oct 13, 2003 at 04:02:20PM +0400, Kirill Korotaev wrote: > > Oh, sorry for misunderstanding. > > In our internal testcase on 8-CPU 8Gb RAM machine with 4gb split kernel > > w/o this patch mount/umount test longs in many-many (>10) times longer. > > Moreover, during the test machine is very slow (due to lock_kernel) > > and typing simple commands takes up to 30 seconds or so. > > I think such a long hangs are due to number of umounts executed > > subsequently. But ofcourse it's not numbers, just for you to know where > > the patch comes from :) > > Is this testcase available and/or trivial? Actually, even if it's trivial > it might just save us the pain of writing the scripts ourselves. no, testcase is not available :( And it uses functionality not available in mainstream kernel. But the problem can be hit with very simple script instead: 1. mount N filesystems. 2. work on them, so that inode cache grows to its maximum possible size (it was 1,000,000 of inodes in our case). 3. umount these filesystems. During operation #3 node is very slow and it is quite noticable on ssh console when typing commands. Kirill