Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756679AbZFJB0s (ORCPT ); Tue, 9 Jun 2009 21:26:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753383AbZFJB0k (ORCPT ); Tue, 9 Jun 2009 21:26:40 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:47510 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752496AbZFJB0j (ORCPT ); Tue, 9 Jun 2009 21:26:39 -0400 Date: Wed, 10 Jun 2009 03:26:05 +0200 From: Ingo Molnar To: Paul Mackerras Cc: Nick Piggin , Linus Torvalds , Rusty Russell , Jeremy Fitzhardinge , "H. Peter Anvin" , Thomas Gleixner , Linux Kernel Mailing List , Andrew Morton , Peter Zijlstra , Avi Kivity , Arjan van de Ven Subject: Re: [benchmark] 1% performance overhead of paravirt_ops on native kernels Message-ID: <20090610012605.GB17743@elte.hu> References: <4A0B62F7.5030802@goop.org> <200906032208.28061.rusty@rustcorp.com.au> <200906041554.37102.rusty@rustcorp.com.au> <20090609093918.GC16940@wotan.suse.de> <20090609111719.GA4463@elte.hu> <20090609121055.GA9158@wotan.suse.de> <20090609122529.GD25586@elte.hu> <18990.61792.721530.554561@cargo.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <18990.61792.721530.554561@cargo.ozlabs.ibm.com> User-Agent: Mutt/1.5.18 (2008-05-17) 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=3.2.5 -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 Content-Length: 641 Lines: 28 * Paul Mackerras wrote: > Ingo Molnar writes: > > > I did this fork overhead measurement some time ago, using > > perfcounters and 'perf': > > Could you post the program? I'd like to try it on some systems > here. I still have it, it was something really, really simple and silly: int main(void) { int i; for (i = 0; i < 8; i++) if (!fork()) wait(0); } Ingo -- 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/