From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752203AbaERIgw (ORCPT ); Sun, 18 May 2014 04:36:52 -0400 Received: from mail-ee0-f54.google.com ([74.125.83.54]:54525 "EHLO mail-ee0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752159AbaERIgp (ORCPT ); Sun, 18 May 2014 04:36:45 -0400 Message-ID: <1400402201.5166.13.camel@marge.simpson.net> Subject: Re: [PATCH] sched/rt: don't try to balance rt_runtime when it is futile From: Mike Galbraith To: paulmck@linux.vnet.ibm.com Cc: Paul Gortmaker , linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, Ingo Molnar , Peter Zijlstra , Steven Rostedt , Thomas Gleixner Date: Sun, 18 May 2014 10:36:41 +0200 In-Reply-To: <20140518052039.GF4570@linux.vnet.ibm.com> References: <1400080115-12339-1-git-send-email-paul.gortmaker@windriver.com> <20140514154459.GE4570@linux.vnet.ibm.com> <1400123931.5175.38.camel@marge.simpson.net> <1400386954.5140.36.camel@marge.simpson.net> <20140518052039.GF4570@linux.vnet.ibm.com> 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 Sat, 2014-05-17 at 22:20 -0700, Paul E. McKenney wrote: > If you are saying that turning on nohz_full doesn't help unless you > also ensure that there is only one runnable task per CPU, I completely > agree. If you are saying something else, you lost me. ;-) Yup, that's it more or less. It's not only single task loads that could benefit from better isolation, but if isolation improving measures are tied to nohz_full, other sensitive loads will suffer if they try to use isolation improvements. -Mike