Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751727AbaAQK42 (ORCPT ); Fri, 17 Jan 2014 05:56:28 -0500 Received: from mail-qe0-f52.google.com ([209.85.128.52]:65221 "EHLO mail-qe0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750974AbaAQK4Z (ORCPT ); Fri, 17 Jan 2014 05:56:25 -0500 MIME-Version: 1.0 In-Reply-To: <20140117102020.GA8751@localhost> References: <20140117102020.GA8751@localhost> Date: Fri, 17 Jan 2014 18:56:24 +0800 Message-ID: Subject: Re: [percpu_counter] 74e72f894: -47.6% aim7 jobs-per-min From: Ming Lei To: Fengguang Wu Cc: LKML , Hugh Dickins Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Fengguang, On Fri, Jan 17, 2014 at 6:20 PM, Fengguang Wu wrote: > Ming Lei, > > We noticed that commit 74e72f894 ("lib/percpu_counter.c: fix > __percpu_counter_add()") introduces -47.6% regression in aim7 brk_test > on a 2S SNB server. Comparing to its parent commit: The commit has a bug, could you apply Hugh's patch[1] to test if the regression can be fixed? If the performance regression is still there, it may be caused by bad performance of this_cpu_add(), then I suggest you to test the patch[2] too without enabling lockdep. [1], http://marc.info/?t=138991497900001&r=1&w=2 [2], http://marc.info/?l=linux-kernel&m=138909074202090&w=2 Thanks, -- Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/