From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from Galois.linutronix.de ([146.0.238.70]:33564 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725929AbeIFQWA (ORCPT ); Thu, 6 Sep 2018 12:22:00 -0400 Date: Thu, 6 Sep 2018 13:46:46 +0200 (CEST) From: Thomas Gleixner To: Dou Liyang cc: Kashyap Desai , Ming Lei , Sumit Saxena , Ming Lei , Christoph Hellwig , Linux Kernel Mailing List , Shivasharan Srikanteshwara , linux-block , Dou Liyang Subject: Re: Affinity managed interrupts vs non-managed interrupts In-Reply-To: Message-ID: References: <20180829084618.GA24765@ming.t460p> <300d6fef733ca76ced581f8c6304bac6@mail.gmail.com> <615d78004495aebc53807156d04d988c@mail.gmail.com> <486f94a563d63c4779498fe8829a546c@mail.gmail.com> <602cee6381b9f435a938bbaf852d07f9@mail.gmail.com> <66256272c020be186becdd7a3f049302@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org On Thu, 6 Sep 2018, Dou Liyang wrote: > At 09/05/2018 06:38 PM, Thomas Gleixner wrote: > > Oh well. This was not intended to magically provide the solution you want > > to have. It merily changed the behaviour of the managed interrupt > > selection, which is a valid thing to do independent of the stuff you want > > to see. > > > > Thank you for clarifying it, I will send the patch independently. > > > As I said that needs more thought and I really can't tell when I have a > > time slot to look at that. > > > > In this period, I am willing to be a volunteer to try to do that you > said in the previous reply. May I? You don't have to ask for permission. It's Open Source :) There are a few things we need to clarify upfront: Right now the pre and post vectors are marked managed and their affinity mask is set to the irq default affinity mask. The default affinity mask is by default ALL cpus, but it can be tweaked both on the kernel command line and via proc. If that mask is only a subset of CPUs and all of them go offline then these vectors are shutdown in managed mode. That means we need to set the affinity mask of the pre and post vectors to possible mask, but that doesn't make much sense either, unless there is a reason to have them marked managed. I think the right solution for these pre/post vectors is to _NOT_ mark them managed and leave them as regular interrupts which can be affinity controlled and also can move freely on hotplug. Christoph? Thanks, Thomas 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_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 A2989C43334 for ; Thu, 6 Sep 2018 11:46:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4604D20857 for ; Thu, 6 Sep 2018 11:46:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4604D20857 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 S1727368AbeIFQWA (ORCPT ); Thu, 6 Sep 2018 12:22:00 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:33564 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725929AbeIFQWA (ORCPT ); Thu, 6 Sep 2018 12:22:00 -0400 Received: from hsi-kbw-5-158-153-52.hsi19.kabel-badenwuerttemberg.de ([5.158.153.52] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1fxskI-0005Zh-EW; Thu, 06 Sep 2018 13:46:46 +0200 Date: Thu, 6 Sep 2018 13:46:46 +0200 (CEST) From: Thomas Gleixner To: Dou Liyang cc: Kashyap Desai , Ming Lei , Sumit Saxena , Ming Lei , Christoph Hellwig , Linux Kernel Mailing List , Shivasharan Srikanteshwara , linux-block , Dou Liyang Subject: Re: Affinity managed interrupts vs non-managed interrupts In-Reply-To: Message-ID: References: <20180829084618.GA24765@ming.t460p> <300d6fef733ca76ced581f8c6304bac6@mail.gmail.com> <615d78004495aebc53807156d04d988c@mail.gmail.com> <486f94a563d63c4779498fe8829a546c@mail.gmail.com> <602cee6381b9f435a938bbaf852d07f9@mail.gmail.com> <66256272c020be186becdd7a3f049302@mail.gmail.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 6 Sep 2018, Dou Liyang wrote: > At 09/05/2018 06:38 PM, Thomas Gleixner wrote: > > Oh well. This was not intended to magically provide the solution you want > > to have. It merily changed the behaviour of the managed interrupt > > selection, which is a valid thing to do independent of the stuff you want > > to see. > > > > Thank you for clarifying it, I will send the patch independently. > > > As I said that needs more thought and I really can't tell when I have a > > time slot to look at that. > > > > In this period, I am willing to be a volunteer to try to do that you > said in the previous reply. May I? You don't have to ask for permission. It's Open Source :) There are a few things we need to clarify upfront: Right now the pre and post vectors are marked managed and their affinity mask is set to the irq default affinity mask. The default affinity mask is by default ALL cpus, but it can be tweaked both on the kernel command line and via proc. If that mask is only a subset of CPUs and all of them go offline then these vectors are shutdown in managed mode. That means we need to set the affinity mask of the pre and post vectors to possible mask, but that doesn't make much sense either, unless there is a reason to have them marked managed. I think the right solution for these pre/post vectors is to _NOT_ mark them managed and leave them as regular interrupts which can be affinity controlled and also can move freely on hotplug. Christoph? Thanks, Thomas