From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752269AbdKAHS4 convert rfc822-to-8bit (ORCPT ); Wed, 1 Nov 2017 03:18:56 -0400 Received: from mout.gmx.net ([212.227.17.21]:56517 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750716AbdKAHSy (ORCPT ); Wed, 1 Nov 2017 03:18:54 -0400 Message-ID: <1509520683.12290.41.camel@gmx.de> Subject: Re: [PATCH RFC 1/2] sched: Minimize the idle cpu selection race window. From: Mike Galbraith To: Atish Patra , Peter Zijlstra Cc: linux-kernel@vger.kernel.org, joelaf@google.com, brendan.jackman@arm.com, jbacik@fb.com, mingo@redhat.com Date: Wed, 01 Nov 2017 08:18:03 +0100 In-Reply-To: <1509519263.12290.30.camel@gmx.de> References: <1509427662-25114-1-git-send-email-atish.patra@oracle.com> <1509427662-25114-2-git-send-email-atish.patra@oracle.com> <20171031082009.rxxa57goto6q5xld@hirez.programming.kicks-ass.net> <1509439705.14765.16.camel@gmx.de> <1509519263.12290.30.camel@gmx.de> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.20.5 Mime-Version: 1.0 Content-Transfer-Encoding: 8BIT X-Provags-ID: V03:K0:d63U0dQNndoRXzrvttawhUJaZsFZluuvqgrjpk6BGIMcuzpzq1h KXDtWEO4k6RfeIL1r9oWKIZTKIVk6VmUQwGQ8LdU9SfIblhDnnNSR5bZUS1jHJX5X5J7642 i6FEWr+HofytVYg+unFJBSQ9XwFP8xSUII+aD7gCciAgq5ItoaIsNSJTwHaqiDarR398/Qg DDL8YynYU9us+/bBl2lGQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:ymYnE6KoJoQ=:HfmXvev95DLeYiL52OsuyH ivExiAv6/BmmYJGOKAMA9O1UN33QepIPxrTjjZsX2ZAMnFlSwdUy5JapWg8DdiE8jVrnvJLWs WdkNPRtVoTTpg7knKXlYepZApwjEJSmk13CU/FCfgrsBFb6FyMKBE54DfNPYIMg4RlBggQYuo 66Ro+fmWPGwjaMF1lvmcHhqyBSCvTUyof20tSQVf+Aou0iE41TxSStmFoDvKvRhckXlJKq60X cxpG2ycU3u8ujfCvgfcVSokgCzPFA6yF2WqDxG8MucKsV9LKhD/Q+L12Z+7cxIvEc9QyZFuGe smsmJpvBMsof0ttIM6Yb+rxtNiTVfgNjvs8khLTr/bFxC5zwbI7q06Q5paftz30MEwu5vtwp4 j1iF+pgg3VZXXCQgfqxDMCpSUVGe3iDBKnJS+2UX0r03OONRXH5Qvxldlq2OlVNLcf5EGaQE4 E9ebaKTxSHAkasnZSIRnQ7GMtr+0eBsgZY4it4VcLG4sG3xJ6q4f/jr4VpYVbMfZDLS9WBiNm 6zi0Z4sDu123LxJ8uGT7fOSK8h/bf/SZDpn9GL6vz7NEkZWKfhoWRdoZj2xE1Gzc7ZWv6UqLn eCsEYABXPd1l44cDqBW6Ns9vS8cCWzKk+yH3fr854UIUCrGHJHHchBc1KOsXvgWcQ5WrNGOfl BEmlc8mcZ5ozJgXYvL6FwR09a5bP0X4Iem4swOIk0O7jXhR8biZb7owlpRC5llbGF4Sec7WUP Om3l7x6+IaSJ7jsgZ7vpj4uOOO3JFXrvw5nJ4Y8MUdiw0Rq5JbiZiwUGxg0xeRvwYE8XJIYaO kyDnIycKcJBD3vyiKRFnhRT0RedvaMk0sc+zmGvSxrC3T7vCoU= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2017-11-01 at 07:54 +0100, Mike Galbraith wrote: > On Wed, 2017-11-01 at 01:08 -0500, Atish Patra wrote: > > > Do you have the schbench configuration somewhere that I can test? I > > tried various configurations but did not > > see any improvement or regression. > > No, as noted, I didn't save anything.  I watched and fiddled with > several configurations on various sized boxen, doing this/that on top > of the reservation thing to try to improve the "it's 100% about perfect > spread" schbench, but didn't like the pricetag, so tossed the lot over > my shoulder and walked away. BTW, the biggest trouble with schbench at that time was not so much about wakeup time stacking (though it was visible), it was using load averages instead of instantaneous state, and sawtoothing therein. -Mike