From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx186.postini.com [74.125.245.186]) by kanga.kvack.org (Postfix) with SMTP id 545CC6B0005 for ; Tue, 9 Apr 2013 01:42:56 -0400 (EDT) Received: by mail-ob0-f180.google.com with SMTP id un3so2402671obb.11 for ; Mon, 08 Apr 2013 22:42:55 -0700 (PDT) Message-ID: <5163AA5A.9010205@gmail.com> Date: Tue, 09 Apr 2013 13:42:50 +0800 From: Simon Jeons MIME-Version: 1.0 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: owner-linux-mm@kvack.org List-ID: To: Cody P Schafer Cc: Andrew Morton , Mel Gorman , Linux MM , LKML 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, 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