Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264366AbUDSMJ7 (ORCPT ); Mon, 19 Apr 2004 08:09:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264381AbUDSMJ7 (ORCPT ); Mon, 19 Apr 2004 08:09:59 -0400 Received: from mail.convergence.de ([212.84.236.4]:31393 "EHLO mail.convergence.de") by vger.kernel.org with ESMTP id S264366AbUDSMJ5 (ORCPT ); Mon, 19 Apr 2004 08:09:57 -0400 Date: Mon, 19 Apr 2004 14:09:57 +0200 From: Johannes Stezenbach To: Jamie Lokier Cc: Eric , linux-kernel@vger.kernel.org, "Stephan T. Lavavej" Subject: Re: Process Creation Speed Message-ID: <20040419120957.GB3764@convergence.de> Mail-Followup-To: Johannes Stezenbach , Jamie Lokier , Eric , linux-kernel@vger.kernel.org, "Stephan T. Lavavej" References: <200404170219.i3H2JYal007333@localhost.localdomain> <200404182115.20922.eric@cisu.net> <20040419030456.GA11717@mail.shareable.org> <200404190043.04358.eric@cisu.net> <20040419094833.GB13007@mail.shareable.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040419094833.GB13007@mail.shareable.org> User-Agent: Mutt/1.5.5.1+cvs20040105i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1072 Lines: 23 Jamie Lokier wrote: > Eric wrote: > > > None of this answers the question which is relevant to linux-kernel: > > > why does process creation take 7.5ms and fail to scale with CPU > > > internal clock speed over a factor of 4 (600MHz x86 to 2.2GHz x86). > > > > The reason it doesn't scale is probably because the kernel always runs at a > > specified speed, 100HZ which leaves 10ms(i believe?) timeslices. I would try > > a HZ patch and bump it up to 1000, i bet you would see a big difference then. > > Hmm. The timer speed shouldn't affect the measured speed of fork() at > all. It might show up if the measuring program is dependent on the > timer in some way, though. http://bulk.fefe.de/scalability/ has some benchmarks on the issue. But I guess the numbers depend heavily on the server/CGI software used. Johannes - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/