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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 25D5DC433E0 for ; Thu, 7 Jan 2021 22:12:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E16272343B for ; Thu, 7 Jan 2021 22:12:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727720AbhAGWLy (ORCPT ); Thu, 7 Jan 2021 17:11:54 -0500 Received: from mga17.intel.com ([192.55.52.151]:41743 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726526AbhAGWLy (ORCPT ); Thu, 7 Jan 2021 17:11:54 -0500 IronPort-SDR: wKtW8U9NL/sGeIuFUhCvs+DmG5iZ2LOiLTUcp7rlL4K4bERL1StlbhWOw3Wy06AnMBI1FlE0rV dv0e59q0q2Lw== X-IronPort-AV: E=McAfee;i="6000,8403,9857"; a="157283921" X-IronPort-AV: E=Sophos;i="5.79,330,1602572400"; d="scan'208";a="157283921" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jan 2021 14:11:08 -0800 IronPort-SDR: f+bOgyqwx0PH6puNAhoPTH1mfbw24NGWYiF8A6eWluQYlYLX29Qi8IQKmnmp/neFXf+U9yhM7V t0lc0NWbdpJA== X-IronPort-AV: E=Sophos;i="5.79,330,1602572400"; d="scan'208";a="566275602" Received: from rchatre-mobl3.amr.corp.intel.com (HELO [10.212.132.29]) ([10.212.132.29]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jan 2021 14:11:07 -0800 Subject: Re: [PATCH V2 1/4] x86/resctrl: Use IPI instead of task_work_add() to update PQR_ASSOC MSR To: Borislav Petkov Cc: tglx@linutronix.de, fenghua.yu@intel.com, tony.luck@intel.com, kuo-lang.tseng@intel.com, shakeelb@google.com, valentin.schneider@arm.com, mingo@redhat.com, babu.moger@amd.com, james.morse@arm.com, hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <17aa2fb38fc12ce7bb710106b3e7c7b45acb9e94.1608243147.git.reinette.chatre@intel.com> <20210106111958.GD5729@zn.tnic> From: Reinette Chatre Message-ID: <516cbcf4-ec80-a81a-c5f4-971fba4b2972@intel.com> Date: Thu, 7 Jan 2021 14:11:07 -0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.1 MIME-Version: 1.0 In-Reply-To: <20210106111958.GD5729@zn.tnic> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Borislav, On 1/6/2021 3:19 AM, Borislav Petkov wrote: > On Thu, Dec 17, 2020 at 02:31:18PM -0800, Reinette Chatre wrote: >> +#ifdef CONFIG_SMP >> +static void update_task_closid_rmid(struct task_struct *t) >> +{ >> + if (task_curr(t)) >> + smp_call_function_single(task_cpu(t), _update_task_closid_rmid, >> + t, 1); >> } >> +#else >> +static void update_task_closid_rmid(struct task_struct *t) >> +{ >> + _update_task_closid_rmid(t); >> +} >> +#endif > > Why the ifdeffery? Why not simply: > > static void update_task_closid_rmid(struct task_struct *t) > { > if (IS_ENABLED(CONFIG_SMP) && task_curr(t)) > smp_call_function_single(task_cpu(t), _update_task_closid_rmid, t, 1); > else > _update_task_closid_rmid(t); > } > > ? > > If no particular reason, I'll change it before committing. There is no particular reason. What you propose is much more readable. Thank you very much. Reinette