From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751581AbXAXOWr (ORCPT ); Wed, 24 Jan 2007 09:22:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751584AbXAXOWr (ORCPT ); Wed, 24 Jan 2007 09:22:47 -0500 Received: from mx1.redhat.com ([66.187.233.31]:37638 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751553AbXAXOWq (ORCPT ); Wed, 24 Jan 2007 09:22:46 -0500 Message-ID: <45B76BAC.4040408@redhat.com> Date: Wed, 24 Jan 2007 09:22:36 -0500 From: Jeff Layton User-Agent: Thunderbird 1.5.0.9 (X11/20061219) MIME-Version: 1.0 To: Andrew Morton CC: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] i_ino uniqueness: alternate approach -- hash the inodes References: <200701161857.l0GIvcaA016196@dantu.rdu.redhat.com> <20070123204648.204b1834.akpm@osdl.org> In-Reply-To: <20070123204648.204b1834.akpm@osdl.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > > What is the additional overhead, expressed in relative terms? ie: as a percentage? Short answer: ~3-4% in a not very scientific test. Long answer: I timed 3 different runs of a program that created and then closed a pipe 10 million times on a patched and unpatched kernel. I then added up the "system" times for each and divided them: unpatched: sys 1m53.959s sys 1m56.083s sys 1m48.055s patched: sys 1m56.899s sys 1m57.027s sys 1m57.031s The result was 1.03803642150033866020. -- Jeff