From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932630Ab1JCVAm (ORCPT ); Mon, 3 Oct 2011 17:00:42 -0400 Received: from arkanian.console-pimps.org ([212.110.184.194]:57854 "EHLO arkanian.console-pimps.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757594Ab1JCU6u (ORCPT ); Mon, 3 Oct 2011 16:58:50 -0400 Subject: Re: [RFC][PATCH 0/5] Signal scalability series From: Matt Fleming To: Oleg Nesterov Cc: Linus Torvalds , Andi Kleen , Tejun Heo , linux-kernel@vger.kernel.org, Tony Luck , Thomas Gleixner , Peter Zijlstra , David Mosberger-Tang In-Reply-To: <20111003163559.GA3957@redhat.com> References: <1317395577-14091-1-git-send-email-matt@console-pimps.org> <1317461738.3375.46.camel@mfleming-mobl1.ger.corp.intel.com> <1317656613.3375.78.camel@mfleming-mobl1.ger.corp.intel.com> <20111003163559.GA3957@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 03 Oct 2011 21:58:40 +0100 Message-ID: <1317675520.3375.82.camel@mfleming-mobl1.ger.corp.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 (2.32.2-1.fc14) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2011-10-03 at 18:35 +0200, Oleg Nesterov wrote: > On 10/03, Matt Fleming wrote: > > > > Oh, are you referring to Oleg's email about the slow down under kvm? > > Yeah, admittedly that's a pretty clear indicator that something is wrong > > with the approach in this patch series. > > Or there was something wrong with my testing, please recheck. I specially > mentioned I was surprised by the numbers. May be kvm, or lockdep... No, I don't think there was anything wrong with your testing method. I ran your command-line under Qemu and saw similar results - with the patches applied the single-threaded case slows down (not by 50%, it looks more like 25%, but that's still unacceptable and not at all what I had anticipated). -- Matt Fleming, Intel Open Source Technology Center