From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9461DC43382 for ; Wed, 26 Sep 2018 15:01:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D6B4214FA for ; Wed, 26 Sep 2018 15:01:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2D6B4214FA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727587AbeIZVO2 convert rfc822-to-8bit (ORCPT ); Wed, 26 Sep 2018 17:14:28 -0400 Received: from Chamillionaire.breakpoint.cc ([146.0.238.67]:37680 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727066AbeIZVO1 (ORCPT ); Wed, 26 Sep 2018 17:14:27 -0400 Received: from bigeasy by Chamillionaire.breakpoint.cc with local (Exim 4.89) (envelope-from ) id 1g5BJE-0002Iy-IN; Wed, 26 Sep 2018 17:01:00 +0200 Date: Wed, 26 Sep 2018 17:01:00 +0200 From: Sebastian Andrzej Siewior To: Peter Zijlstra Cc: will.deacon@arm.com, mingo@kernel.org, linux-kernel@vger.kernel.org, longman@redhat.com, andrea.parri@amarulasolutions.com, tglx@linutronix.de Subject: Re: [RFC][PATCH 0/3] locking/qspinlock: Improve determinism for x86 Message-ID: <20180926150059.ua5576guhns5osgj@breakpoint.cc> References: <20180926110117.405325143@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: <20180926110117.405325143@infradead.org> User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018-09-26 13:01:17 [+0200], Peter Zijlstra wrote: > In particular this ordering ensures a concurrent unlock cannot trigger > the uncontended handoff. Also it ensures that if the xchg() happens > after a (successful) trylock, we must observe that LOCKED bit. so I backported a bunch of atomic files and qspinlock back to v4.9-RT in order to get these patches applied. The backported kernel booted and showed the same symptomps within seconds (those I reported last FR). With those three patches ontop I have the Core2Duo 10 minutes in testing without any issues… Sebastian