From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965635AbaH1Jyo (ORCPT ); Thu, 28 Aug 2014 05:54:44 -0400 Received: from service87.mimecast.com ([91.220.42.44]:56996 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936358AbaH1Jyn convert rfc822-to-8bit (ORCPT ); Thu, 28 Aug 2014 05:54:43 -0400 Message-ID: <53FEFC7E.3060803@arm.com> Date: Thu, 28 Aug 2014 10:55:10 +0100 From: Sudeep Holla User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Will Deacon CC: Sudeep Holla , "byungchul.park@lge.com" , Catalin Marinas , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 1/2] Revert "arm64: use cpu_online_mask when using forced irq_set_affinity" References: <1409131806-11276-1-git-send-email-byungchul.park@lge.com> <20140828093826.GC22580@arm.com> <53FEFB42.5060600@arm.com> <20140828095050.GE22580@arm.com> In-Reply-To: <20140828095050.GE22580@arm.com> X-OriginalArrivalTime: 28 Aug 2014 09:54:39.0067 (UTC) FILETIME=[150E92B0:01CFC2A6] X-MC-Unique: 114082810544101201 Content-Type: text/plain; charset=WINDOWS-1252; format=flowed Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28/08/14 10:50, Will Deacon wrote: > On Thu, Aug 28, 2014 at 10:49:54AM +0100, Sudeep Holla wrote: >> >> >> On 28/08/14 10:38, Will Deacon wrote: >>> On Wed, Aug 27, 2014 at 10:30:06AM +0100, byungchul.park@lge.com wrote: >>>> From: Byungchul Park >>>> >>>> This reverts commit 601c942176d8ad8334118bddb747e3720bed24f8. >>>> >>>> This patch is designed to ensure that the cpu being offlined is not >>>> present in the affinity mask. But it is a bad idea to overwrite the >>>> affinity variable with cpu_online_mask, even in case that the current >>>> affinity already includes onlined cpus. >>>> >>>> So revert this patch to replace it with another one doing exactly >>>> what it intends. >>> >>> Sudeep: what's the right way forward for this? There seems to be general >>> agreement that the existing code is broken, but a bunch of different >>> `fixes'. Can we just take a straight port of what tglx proposed for ARM? >>> (changing force to false) >>> >> >> Yes I agree but for that we need agreement from rmk and hence I asked to >> wait till we hear from rmk. Main issue raised by rmk is if some other >> interrupt controller implementation decide not to migrate away when >> force is false(theoretically possible). > > Okey doke. Whatever solution we take should be the same for arm and arm64, > so I'll leave it with you. > tglx just confirmed that interrupt controller implementation using force flag must use online_cpumask. So converting to false should be fine. So once rmk agrees for ARM, we can apply this revert and change to false for ARM64 also. Regards, Sudeep