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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 42A61C04ABB for ; Tue, 11 Sep 2018 09:09:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0811E2086A for ; Tue, 11 Sep 2018 09:09:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0811E2086A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.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 S1726945AbeIKOHy (ORCPT ); Tue, 11 Sep 2018 10:07:54 -0400 Received: from verein.lst.de ([213.95.11.211]:41780 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726554AbeIKOHx (ORCPT ); Tue, 11 Sep 2018 10:07:53 -0400 Received: by newverein.lst.de (Postfix, from userid 2407) id 3C85768C8A; Tue, 11 Sep 2018 11:13:54 +0200 (CEST) Date: Tue, 11 Sep 2018 11:13:54 +0200 From: Christoph Hellwig To: Thomas Gleixner Cc: Dou Liyang , 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 Message-ID: <20180911091354.GA9898@lst.de> References: <602cee6381b9f435a938bbaf852d07f9@mail.gmail.com> <66256272c020be186becdd7a3f049302@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 06, 2018 at 01:46:46PM +0200, Thomas Gleixner wrote: > 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. Yes, agreed. Marking the pre/post vector as managed was a mistake (and I don't think it even was intentional, at least on my part).