From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754011AbbJTItJ (ORCPT ); Tue, 20 Oct 2015 04:49:09 -0400 Received: from mail-wi0-f169.google.com ([209.85.212.169]:33987 "EHLO mail-wi0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753439AbbJTItA (ORCPT ); Tue, 20 Oct 2015 04:49:00 -0400 Date: Tue, 20 Oct 2015 10:48:56 +0200 From: Ingo Molnar To: Ling Ma Cc: peterz@infradead.org, mingo@redhat.com, linux-kernel@vger.kernel.org, Ma Ling , Waiman.Long@hpe.com Subject: Re: [RFC PATCH] qspinlock: Improve performance by reducing load instruction rollback Message-ID: <20151020084856.GA15328@gmail.com> References: <1445221642-15319-1-git-send-email-ling.ma.program@gmail.com> <20151019075823.GB22488@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Ling Ma wrote: > > So it would be nice to create a new user-space spinlock testing facility, via > > a new 'perf bench spinlock' feature or so. That way others can test and > > validate your results on different hardware as well. > > Attached the spinlock test module . Queued spinlock will run very slowly in user > space because process switch context, it is OK for spinlock-test implementation > with kernel module ? Not sure what you mean by 'because process switch context': if you pin the test tasks to individual CPUs and make sure there's nothing else running it should be equivalent to kernel-space execution. Thanks, Ingo