From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id BC7A66B003D for ; Fri, 11 Dec 2009 08:52:02 -0500 (EST) Message-ID: <4B224E7A.2060708@redhat.com> Date: Fri, 11 Dec 2009 08:51:54 -0500 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH] vmscan: limit concurrent reclaimers in shrink_zone References: <20091210185626.26f9828a@cuia.bos.redhat.com> <28c262360912101803i7b43db78se8cf9ec61d92ee0f@mail.gmail.com> <4B2235F0.4080606@redhat.com> <28c262360912110541m2839e151hc9d49b0c251e1b67@mail.gmail.com> In-Reply-To: <28c262360912110541m2839e151hc9d49b0c251e1b67@mail.gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Minchan Kim Cc: lwoodman@redhat.com, kosaki.motohiro@jp.fujitsu.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, aarcange@redhat.com List-ID: On 12/11/2009 08:41 AM, Minchan Kim wrote: > Hi, Larry. > > On Fri, Dec 11, 2009 at 9:07 PM, Larry Woodman wrote: >> Minchan Kim wrote: >>> >>> I like this. but why do you select default value as constant 8? >>> Do you have any reason? >>> >>> I think it would be better to select the number proportional to NR_CPU. >>> ex) NR_CPU * 2 or something. >>> >>> Otherwise looks good to me. >>> >>> Reviewed-by: Minchan Kim >>> >>> >> >> This is a per-zone count so perhaps a reasonable default is the number of >> CPUs on the >> NUMA node that the zone resides on ? > > For example, It assume one CPU per node. > It means your default value is 1. > On the CPU, process A try to reclaim HIGH zone. > Process B want to reclaim NORMAL zone. > But Process B can't enter reclaim path sincev throttle default value is 1 > Even kswap can't reclaim. 1) the value is per zone, so process B can go ahead 2) kswapd is always excempt from this limit, since there is only 1 kswapd per node anyway -- All rights reversed. -- 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