From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752752AbbJOKyo (ORCPT ); Thu, 15 Oct 2015 06:54:44 -0400 Received: from foss.arm.com ([217.140.101.70]:34895 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752671AbbJOKyn (ORCPT ); Thu, 15 Oct 2015 06:54:43 -0400 Date: Thu, 15 Oct 2015 11:54:38 +0100 From: Catalin Marinas To: "Suzuki K. Poulose" Cc: linux-arm-kernel@lists.infradead.org, mark.rutland@arm.com, Vladimir.Murzin@arm.com, steve.capper@linaro.org, ryan.arnold@linaro.org, ard.biesheuvel@linaro.org, marc.zyngier@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, edward.nevill@linaro.org, aph@redhat.com, james.morse@arm.com, andre.przywara@arm.com, dave.martin@arm.com, christoffer.dall@linaro.org Subject: Re: [PATCH v3 13/24] arm64: Populate cpuinfo after notify_cpu_starting Message-ID: <20151015105438.GL4239@e104818-lin.cambridge.arm.com> References: <1444756952-31145-1-git-send-email-suzuki.poulose@arm.com> <1444756952-31145-14-git-send-email-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1444756952-31145-14-git-send-email-suzuki.poulose@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 13, 2015 at 06:22:21PM +0100, Suzuki K. Poulose wrote: > This patch delays populating the cpuinfo for a new (hotplugged) > CPU until the notifiers have executed. This will enable us to verify > if the new (hotplugged) CPU has all the capabilities which the system > already has. If it doesn't, we could prevent it from turning online and > also modifying the system wide feature register status. Just a question here: do we expect the notifiers to enable certain features that we check later? AFAICT, the checking is done on the feature registers which don't change after notifiers, so we could as well block the booting before any notifier is run. -- Catalin