From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763687AbXGZGXR (ORCPT ); Thu, 26 Jul 2007 02:23:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753300AbXGZGXG (ORCPT ); Thu, 26 Jul 2007 02:23:06 -0400 Received: from ug-out-1314.google.com ([66.249.92.168]:16805 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752047AbXGZGXE (ORCPT ); Thu, 26 Jul 2007 02:23:04 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=r1NZ39GPOC1N3nZ37xM2lIo6++3XJVPzzOzH4tOtCVekSfcIlgFNNwj8yOG2wTFZiRYtNg+tHO1VBcr6eGQJMqsruvgl4MPnyvaSPecFB30w83aChL35h2wLFDrqTLOIv2afTTnvBOd+7ufyQhx3jYh3AYa78I1ILJy+6v4kyX0= Message-ID: <7e0bae390707252323k2552c701x5673c55ff2cf119e@mail.gmail.com> Date: Thu, 26 Jul 2007 13:23:03 +0700 From: "Andika Triwidada" To: "Rene Herman" Subject: Re: updatedb Cc: "Robert Deaton" , linux-kernel@vger.kernel.org, "ck list" , linux-mm@kvack.org In-Reply-To: <46A81C39.4050009@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <367a23780707250830i20a04a60n690e8da5630d39a9@mail.gmail.com> <46A773EA.5030103@gmail.com> <46A81C39.4050009@gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 7/26/07, Rene Herman wrote: > On 07/25/2007 07:15 PM, Robert Deaton wrote: > > > On 7/25/07, Rene Herman wrote: > > >> And there we go again -- off into blabber-land. Why does swap-prefetch > >> help updatedb? Or doesn't it? And if it doesn't, why should anyone > >> trust anything else someone who said it does says? > > > I don't think anyone has ever argued that swap-prefetch directly helps > > the performance of updatedb in any way > > People have argued (claimed, rather) that swap-prefetch helps their system > after updatedb has run -- you are doing so now. > > > however, I do recall people mentioning that updatedb, being a ram > > intensive task, will often cause things to be swapped out while it runs > > on say a nightly cronjob. > > Problem spot no. 1. > > RAM intensive? If I run updatedb here, it never grows itself beyond 2M. Yes, > two. I'm certainly willing to accept that me and my systems are possibly not > the reference but assuming I'm _very_ special hasn't done much for me either > in the past. Might be insignificant, but updatedb calls find (~2M) and sort (~26M). Definitely not RAM intensive though (RAM is 1GB). > > The thing updatedb does do, or at least has the potential to do, is fill > memory with cached inodes/dentries but Linux does not swap to make room for > caches. So why will updatedb "often cause things to be swapped out"? > [ snip ]