From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx117.postini.com [74.125.245.117]) by kanga.kvack.org (Postfix) with SMTP id 359026B005D for ; Fri, 28 Sep 2012 10:47:26 -0400 (EDT) Received: from /spool/local by e23smtp02.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sat, 29 Sep 2012 00:45:21 +1000 Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay05.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q8SEbgtY37027916 for ; Sat, 29 Sep 2012 00:37:43 +1000 Received: from d23av02.au.ibm.com (loopback [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q8SElHV9031912 for ; Sat, 29 Sep 2012 00:47:18 +1000 Message-ID: <5065B84F.6060204@linux.vnet.ibm.com> Date: Fri, 28 Sep 2012 20:16:39 +0530 From: "Srivatsa S. Bhat" MIME-Version: 1.0 Subject: Re: [PATCH] CPU hotplug, writeback: Don't call writeback_set_ratelimit() too often during hotplug References: <20120924102324.GA22303@aftab.osrc.amd.com> <20120924142305.GD12264@quack.suse.cz> <20120924143609.GH22303@aftab.osrc.amd.com> <20120924201650.6574af64.conny.seidel@amd.com> <20120924181927.GA25762@aftab.osrc.amd.com> <5060AB0E.3070809@linux.vnet.ibm.com> <5060C714.8030606@linux.vnet.ibm.com> <20120928122719.GA3067@localhost> In-Reply-To: <20120928122719.GA3067@localhost> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Fengguang Wu Cc: Borislav Petkov , Conny Seidel , Jan Kara , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Peter Zijlstra , Andrew Morton , Johannes Weiner , "Paul E. McKenney" , Thomas Gleixner On 09/28/2012 05:57 PM, Fengguang Wu wrote: > On Tue, Sep 25, 2012 at 02:18:20AM +0530, Srivatsa S. Bhat wrote: >> >> From: Srivatsa S. Bhat >> >> The CPU hotplug callback related to writeback calls writeback_set_ratelimit() >> during every state change in the hotplug sequence. This is unnecessary >> since num_online_cpus() changes only once during the entire hotplug operation. >> >> So invoke the function only once per hotplug, thereby avoiding the >> unnecessary repetition of those costly calculations. >> >> Signed-off-by: Srivatsa S. Bhat >> --- > > Looks good to me. I'll include it in the writeback tree. > Great, thanks! Regards, Srivatsa S. Bhat -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org