From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754043AbcDFWIv (ORCPT ); Wed, 6 Apr 2016 18:08:51 -0400 Received: from mail-bn1bon0119.outbound.protection.outlook.com ([157.56.111.119]:26400 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753411AbcDFWIt (ORCPT ); Wed, 6 Apr 2016 18:08:49 -0400 Authentication-Results: linux.com; dkim=none (message not signed) header.d=none;linux.com; dmarc=none action=none header.from=hpe.com; Message-ID: <57058544.1000204@hpe.com> Date: Wed, 6 Apr 2016 17:53:08 -0400 From: Waiman Long User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.12) Gecko/20130109 Thunderbird/10.0.12 MIME-Version: 1.0 To: Christoph Lameter CC: Nikolay Borisov , "Theodore Ts'o" , Andreas Dilger , Tejun Heo , , , Scott J Norton , Douglas Hatch , Toshimitsu Kani Subject: Re: [PATCH 2/3] percpu_stats: Simple per-cpu statistics count helper functions References: <1459566578-30221-1-git-send-email-Waiman.Long@hpe.com> <1459566578-30221-3-git-send-email-Waiman.Long@hpe.com> <57021969.8050504@kyup.com> <5702A053.5030404@hpe.com> In-Reply-To: Content-Type: text/plain; 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>>>> + preempt_disable(); >>>> + pstat = this_cpu_ptr(&pcs->stats[stat]); >>>> + *pstat += cnt; >>>> + preempt_enable(); >>>> +} >>> pstat = get_cpu_ptr(&pcs->stats[stat]); >>> *pstat += cnt; >>> put_cpu_ptr(&pcs->stats[stat]); >>> >>> It will generate identical code but this one uses APIs, making the >>> intention clearer. But as I said this is just a minor nit. >>> >>> you can add my Reviewed-by: Nikolay Borisov for this >>> particular patch. >> Yes, that will certainly make it look nicer. I will update the patch once I >> get feedback from my other ext4 patches. > Why not > > this_cpu_add(pci->stats[stat], cnt) > > This is a single instruction on x86. > Yes, using this_cpu_add() will be even simpler. Cheers, Longman