From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932688AbcJGT6z (ORCPT ); Fri, 7 Oct 2016 15:58:55 -0400 Received: from mail-oi0-f67.google.com ([209.85.218.67]:34019 "EHLO mail-oi0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752666AbcJGT6q (ORCPT ); Fri, 7 Oct 2016 15:58:46 -0400 MIME-Version: 1.0 In-Reply-To: <57F7F9AF.2010609@canonical.com> References: <57F7F9AF.2010609@canonical.com> From: Linus Torvalds Date: Fri, 7 Oct 2016 12:57:47 -0700 X-Google-Sender-Auth: kqfpqyu55L2zoBdyHvk6GZei0uk Message-ID: Subject: Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes To: Joseph Salisbury Cc: Peter Zijlstra , Mike Galbraith , Thomas Gleixner , LKML , Ingo Molnar Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 7, 2016 at 12:38 PM, Joseph Salisbury wrote: > > A kernel bug report was opened against Ubuntu [0]. After a kernel > bisect, it was found that reverting the following commit resolved this bug: Hmm. Interesting, and it sounds like we should revert that unless somebody figures out *why* following the rules wrt cfq updates causes problems. But I also wonder what the Ubuntu kernel config is. Does Ubuntu enable CONFIG_SCHED_AUTOGROUP=y, for example? Because regardless of any other scheduler issues, autogrouping *should* mean that when you run some CPU hogger in one session, that should still balance all CPU time with other sessions.. I'm not seeing anything odd on my xps13, which should have a similar CPU to the X1 Carbon. Linus