From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932276AbdC2SGE (ORCPT ); Wed, 29 Mar 2017 14:06:04 -0400 Received: from mail-wr0-f196.google.com ([209.85.128.196]:34880 "EHLO mail-wr0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751717AbdC2SGD (ORCPT ); Wed, 29 Mar 2017 14:06:03 -0400 Date: Wed, 29 Mar 2017 20:05:58 +0200 From: Ingo Molnar To: Randy Dunlap Cc: Radu Rendec , linux-kernel@vger.kernel.org Subject: Re: Impact of CONFIG_PARAVIRT=y / mmap benchmark Message-ID: <20170329180558.GA31692@gmail.com> References: <1490721452.1907.25.camel@arista.com> <2639617f-fe7c-e6cb-c7bf-094a73490228@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2639617f-fe7c-e6cb-c7bf-094a73490228@infradead.org> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Randy Dunlap wrote: > On 03/28/17 10:17, Radu Rendec wrote: > > Hi, > > > > I'm trying to assess the performance impact of enabling PARAVIRT (and > > XEN) in a custom kernel configuration. I came across a very old thread > > (https://lkml.org/lkml/2009/5/13/449) on this topic and the conclusion > > back then was that the performance impact was (arguably) around 1%. > > > > Does anyone still have a copy of Ingo Molnar's mmap-perf.c program (the > > old link is broken)? Would it still be relevant to use it for measuring > > performance in case of PARAVIRT? > > > > Last but not least, has anyone looked into PARAVIRT performance more > > recently? > > > > Thank you! > > > > Best regards, > > Radu Rendec > > I have mmap-perf.c that says: > /* Copyright Ingo Molnar (c) 2006 */ > > and no license info... > Ingo? It's GPL v2, like the kernel. Thanks, Ingo