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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 06298C5519F for ; Fri, 20 Nov 2020 14:53:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CEFF8221F8 for ; Fri, 20 Nov 2020 14:53:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728162AbgKTOx1 (ORCPT ); Fri, 20 Nov 2020 09:53:27 -0500 Received: from foss.arm.com ([217.140.110.172]:50398 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727053AbgKTOx0 (ORCPT ); Fri, 20 Nov 2020 09:53:26 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 66E221396; Fri, 20 Nov 2020 06:53:26 -0800 (PST) Received: from [192.168.2.21] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0A4073F70D; Fri, 20 Nov 2020 06:53:24 -0800 (PST) Subject: Re: [PATCH 1/2] x86/intel_rdt: Check monitor group vs control group membership earlier To: Valentin Schneider Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Fenghua Yu , Reinette Chatre , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" References: <20201118180030.22764-1-valentin.schneider@arm.com> <20201118180030.22764-2-valentin.schneider@arm.com> From: James Morse Message-ID: <613d0854-597e-6ed7-05ca-70310c7b887d@arm.com> Date: Fri, 20 Nov 2020 14:53:15 +0000 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20201118180030.22764-2-valentin.schneider@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Valentin, On 18/11/2020 18:00, Valentin Schneider wrote: > A task can only be moved between monitor groups if both groups belong to > the same control group. This is checked fairly late however: by that time > we already have appended a task_work() callback. (is that a problem? It's needed to do the kfree()) > Check the validity of the move before getting anywhere near task_work > callbacks. This saves the kzalloc()/task_work_add() if it wasn't going to be necessary. Reviewed-by: James Morse Thanks, James