Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933176AbaGOTYI (ORCPT ); Tue, 15 Jul 2014 15:24:08 -0400 Received: from mail-we0-f177.google.com ([74.125.82.177]:42874 "EHLO mail-we0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932850AbaGOTYE (ORCPT ); Tue, 15 Jul 2014 15:24:04 -0400 Message-ID: <1405452240.5117.87.camel@marge.simpson.net> Subject: Re: [PATCH v4 6/7] sched: add function nr_running_cpu to expose number of tasks running on cpu From: Mike Galbraith To: Peter Zijlstra Cc: Thomas Gleixner , Tim Chen , Herbert Xu , "H. Peter Anvin" , "David S.Miller" , Ingo Molnar , Chandramouli Narayanan , Vinodh Gopal , James Guilford , Wajdi Feghali , Jussi Kivilinna , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Date: Tue, 15 Jul 2014 21:24:00 +0200 In-Reply-To: <20140715190339.GQ6758@twins.programming.kicks-ass.net> References: <20140714181738.GI9918@twins.programming.kicks-ass.net> <1405364908.2970.729.camel@schen9-DESK> <20140714191504.GO9918@twins.programming.kicks-ass.net> <1405367450.2970.750.camel@schen9-DESK> <20140715095045.GV9918@twins.programming.kicks-ass.net> <20140715120728.GR3588@twins.programming.kicks-ass.net> <1405435525.5744.29.camel@marge.simpson.net> <20140715145346.GM9918@twins.programming.kicks-ass.net> <1405447615.5117.36.camel@marge.simpson.net> <20140715190339.GQ6758@twins.programming.kicks-ass.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2014-07-15 at 21:03 +0200, Peter Zijlstra wrote: > On Tue, Jul 15, 2014 at 08:06:55PM +0200, Mike Galbraith wrote: > > On Tue, 2014-07-15 at 16:53 +0200, Peter Zijlstra wrote: > > > On Tue, Jul 15, 2014 at 04:45:25PM +0200, Mike Galbraith wrote: > > > > > > > > 3.0.101-default 3.753363 usecs/loop -- avg 3.770737 530.4 KHz 1.000 > > > > 3.14.10-default 4.145348 usecs/loop -- avg 4.139987 483.1 KHz .910 1.000 > > > > 3.15.4-default 4.355594 usecs/loop -- avg 4.351961 459.6 KHz .866 .951 1.000 > > > > 3.16.0-default 4.537279 usecs/loop -- avg 4.543532 440.2 KHz .829 .911 .957 > > > > > > > > 3.0.101-smp 3.692377 usecs/loop -- avg 3.690774 541.9 KHz 1.000 > > > > 3.14.10-smp 4.010009 usecs/loop -- avg 4.009019 498.9 KHz .920 > > > > 3.15.4-smp 3.882398 usecs/loop -- avg 3.884095 514.9 KHz .950 > > > > 3.16.0-master 4.061003 usecs/loop -- avg 4.058244 492.8 KHz .909 > > > > > > Urgh,.. I need to go fix that :/ > > > > I'm poking about. It's not just one thing 'course, just lots of change > > adding up to less than wonderful. Idle changes are costing some, for > > obese config, avg goop. The select_next_task() reorganization appears > > to be costing, but eyeballing, I can see no excuse for that at all. > > How is the idle stuff costing, cpu-affine pipe-test should pretty much > peg a cpu at 100%, right? Or did I mis-understand and are you running a > loose pipe-test? Exactly, I'm measuring the cost of popping in and out of idle while trying to reclaim overlap (which doesn't exist in pipe-test case). -Mike -- 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/