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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 24FA2C4321A for ; Tue, 11 Jun 2019 13:15:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F303120673 for ; Tue, 11 Jun 2019 13:14:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390593AbfFKNO7 (ORCPT ); Tue, 11 Jun 2019 09:14:59 -0400 Received: from foss.arm.com ([217.140.110.172]:32966 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388792AbfFKNO6 (ORCPT ); Tue, 11 Jun 2019 09:14:58 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C901B344; Tue, 11 Jun 2019 06:14:57 -0700 (PDT) Received: from [0.0.0.0] (e107985-lin.cambridge.arm.com [10.1.194.38]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6CB4F3F557; Tue, 11 Jun 2019 06:14:56 -0700 (PDT) Subject: Re: [PATCH HACK RFC] cpu: Prevent late-arriving interrupts from disrupting offline To: paulmck@linux.ibm.com Cc: Mark Rutland , Peter Zijlstra , tglx@linutronix.de, mingo@kernel.org, jpoimboe@redhat.com, mojha@codeaurora.org, linux-kernel@vger.kernel.org References: <20190602011253.GA6167@linux.ibm.com> <20190603083848.GB3436@hirez.programming.kicks-ass.net> <20190603114455.GA16119@lakrids.cambridge.arm.com> <20190604074549.GP28207@linux.ibm.com> <6eb5d59f-37d0-0aab-1fc0-fcf48cc4164f@arm.com> <20190608164158.GK28207@linux.ibm.com> From: Dietmar Eggemann Message-ID: <16a424d1-0ab7-7e81-5c4f-93da23519b1d@arm.com> Date: Tue, 11 Jun 2019 15:14:54 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190608164158.GK28207@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/8/19 6:41 PM, Paul E. McKenney wrote: > On Tue, Jun 04, 2019 at 03:29:32PM +0200, Dietmar Eggemann wrote: >> On 6/4/19 9:45 AM, Paul E. McKenney wrote: >>> On Mon, Jun 03, 2019 at 03:39:18PM +0200, Dietmar Eggemann wrote: >>>> On 6/3/19 1:44 PM, Mark Rutland wrote: >>>>> On Mon, Jun 03, 2019 at 10:38:48AM +0200, Peter Zijlstra wrote: >>>>>> On Sat, Jun 01, 2019 at 06:12:53PM -0700, Paul E. McKenney wrote: >>>>>>> Scheduling-clock interrupts can arrive late in the CPU-offline process, [...] >>> And it looks like the reason I dropped it was that I didn't get any >>> response from the maintainer. I sent a message to this effect to >>> linux-arm-kernel@lists.infradead.org and linux@arm.linux.org.uk on May >>> 21, 2015. >>> >>> So here it is again. ;-) >>> >>> I have queued this locally. Left to myself, I add the two of you on its >>> Cc: list and run it through my normal process. But given the history, >>> I would still want either an ack from the maintainer or, better, for >>> the maintainer to take the patch. >>> >>> Or is there a better way for us to proceed on this? >> >> You could send this patch also to >> linux-arm-kernel@lists.infradead.org and cc rmk to get his opinion >> on the patch. > > OK, please let me know how the testing goes. My thought is to send the > patch as you suggest with your Tested-by. Tested your patch on top of v5.2-rc4* on Arm TC2 (32bit) and CPU hotplug stress test. W/o your patch, the test fails within seconds since CPUs are not coming up again. W/ your patch, the test runs for hours just fine. You can add my: Tested-by: Dietmar Eggemann * just for the record: one additional unrelated patch (to disable the NOR flash) is necessary on Arm TC2: https://patchwork.kernel.org/patch/10968391 .