From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754739AbbFKSw0 (ORCPT ); Thu, 11 Jun 2015 14:52:26 -0400 Received: from www.linutronix.de ([62.245.132.108]:57840 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752442AbbFKSwY (ORCPT ); Thu, 11 Jun 2015 14:52:24 -0400 Date: Thu, 11 Jun 2015 20:52:27 +0200 (CEST) From: Thomas Gleixner To: Mike Galbraith cc: LKML , Peter Zijlstra , Ingo Molnar , Steven Rostedt Subject: Re: RFC: futex_wait() can DoS the tick In-Reply-To: <1434048238.3396.59.camel@gmail.com> Message-ID: References: <1433940278.6814.66.camel@gmail.com> <1433957421.6306.28.camel@gmail.com> <1433989634.3411.15.camel@gmail.com> <1434022875.4051.5.camel@gmail.com> <1434048238.3396.59.camel@gmail.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 11 Jun 2015, Mike Galbraith wrote: > On Thu, 2015-06-11 at 15:13 +0200, Thomas Gleixner wrote: > > > The kernel does not care whether the actual interrupt happens or the > > timer is expired by other means. > > Final question: Notabug explanation fits.. but why would the behavior > delta be so radical and repeatable w/wo deadline timer on some boxen? Good question. Cannot answer that w/o looking at traces. Thanks, tglx