Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934560Ab3DIFm6 (ORCPT ); Tue, 9 Apr 2013 01:42:58 -0400 Received: from mail-ob0-f176.google.com ([209.85.214.176]:36641 "EHLO mail-ob0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752414Ab3DIFm4 (ORCPT ); Tue, 9 Apr 2013 01:42:56 -0400 Message-ID: <5163AA5A.9010205@gmail.com> Date: Tue, 09 Apr 2013 13:42:50 +0800 From: Simon Jeons User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: Cody P Schafer CC: Andrew Morton , Mel Gorman , Linux MM , LKML Subject: Re: [PATCH 1/3] mm/page_alloc: factor out setting of pcp->high and pcp->batch. References: <1365194030-28939-1-git-send-email-cody@linux.vnet.ibm.com> <1365194030-28939-2-git-send-email-cody@linux.vnet.ibm.com> <5160CDD8.3050908@gmail.com> <516300C7.7000008@linux.vnet.ibm.com> In-Reply-To: <516300C7.7000008@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1512 Lines: 37 Hi Cody, On 04/09/2013 01:39 AM, Cody P Schafer wrote: > On 04/06/2013 06:37 PM, Simon Jeons wrote: >> Hi Cody, >> On 04/06/2013 04:33 AM, Cody P Schafer wrote: >>> Creates pageset_set_batch() for use in setup_pageset(). >>> pageset_set_batch() imitates the functionality of >>> setup_pagelist_highmark(), but uses the boot time >>> (percpu_pagelist_fraction == 0) calculations for determining ->high >> >> Why need adjust pcp->high, pcp->batch during system running? What's the >> requirement? >> > > There is currently a sysctl (which I patch later in this series) which > allows adjusting the ->high mark (and, indirectly, ->batch). > Additionally, memory hotplug changes ->high and ->batch due to the > zone size changing (essentially, zone->managed_pages and > zone->present_pages have changed) , meaning that zone_batchsize(), > which is used at boot to set ->batch and (indirectly) ->high has a > different output. Thanks for your explain. I'm curious about this sysctl, when need adjust the ->high, ->batch during system running except memory hotplug which will change zone size? > > Note that in addition to the 2 users of this functionality mentioned > here, I'm currently working on anther resizer of zones (runtime NUMA > reconfiguration). > -- 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/