From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760681AbbLCRIc (ORCPT ); Thu, 3 Dec 2015 12:08:32 -0500 Received: from foss.arm.com ([217.140.101.70]:50325 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752337AbbLCRIb (ORCPT ); Thu, 3 Dec 2015 12:08:31 -0500 Date: Thu, 3 Dec 2015 17:08:21 +0000 From: Mark Rutland To: "Suzuki K. Poulose" Cc: linux-arm-kernel@lists.infradead.org, marc.zyngier@arm.com, linux-kernel@vger.kernel.org, will.deacon@arm.com, catalin.marinas@arm.com Subject: Re: [PATCH v2 2/6] arm64: Move kill_cpu_early to smp.c Message-ID: <20151203170820.GB3527@leverpostej> References: <1448982731-17182-1-git-send-email-suzuki.poulose@arm.com> <1448982731-17182-3-git-send-email-suzuki.poulose@arm.com> <20151201152826.GA28370@leverpostej> <565DC5DB.7070905@arm.com> <20151201163138.GA29045@leverpostej> <565DDB2E.2010308@arm.com> <20151201175254.GD29045@leverpostej> <565DE289.2000105@arm.com> <20151201185028.GF29045@leverpostej> <56606FA3.3010802@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <56606FA3.3010802@arm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 03, 2015 at 04:36:51PM +0000, Suzuki K. Poulose wrote: > On 01/12/15 18:50, Mark Rutland wrote: > >On Tue, Dec 01, 2015 at 06:10:17PM +0000, Suzuki K. Poulose wrote: > >>On 01/12/15 17:52, Mark Rutland wrote: > >>>On Tue, Dec 01, 2015 at 05:38:54PM +0000, Suzuki K. Poulose wrote: > >>>>On 01/12/15 16:31, Mark Rutland wrote: > >>OK. So the flag will also be used for CPUs which are stuck-in-the-kernel > >>with MMU turned on. e.g, a CPU (using spin-table) we try to bring down > >>in kill_cpu_early(). Correct ? > > > >Yes. > > > >We'd also pad it such that nothing else shares the same writeback > >granule, and when writing to it with the MMU off we can invalidate the > >stale cached copy. > > I have started working on this approach. But the changes are a bit more invasive > and looks more like suited for 4.5. We could push this series(which doesn't change > the current behavior as it is in 4.4-rc3, except for the code movement) to fix > the ASID sanity check and introduce the synchronisation part in 4.5. > What do you think ? I'm happy with that. I agree this patch as-is doesn't make matters worse. Thanks, Mark.