From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 1E6486B00B3 for ; Fri, 2 Jan 2009 05:29:18 -0500 (EST) Received: by gxk12 with SMTP id 12so3703144gxk.14 for ; Fri, 02 Jan 2009 02:29:17 -0800 (PST) Message-ID: <28c262360901020229k55d47445yc9a6c9c7aa3e9c66@mail.gmail.com> Date: Fri, 2 Jan 2009 19:29:16 +0900 From: "MinChan Kim" Subject: Re: [PATCH] mm: stop kswapd's infinite loop at high order allocation take2 In-Reply-To: <2f11576a0901020200t3a6dadf5qa944432cd9fd8873@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20081231115332.GB20534@csn.ul.ie> <20081231215934.1296.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20090101021240.A057.KOSAKI.MOTOHIRO@jp.fujitsu.com> <28c262360901020155l3a9260b5h3c79d4b23a213825@mail.gmail.com> <2f11576a0901020200t3a6dadf5qa944432cd9fd8873@mail.gmail.com> Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: Mel Gorman , LKML , linux-mm , Andrew Morton , Nick Piggin , wassim dagash List-ID: On Fri, Jan 2, 2009 at 7:00 PM, KOSAKI Motohiro wrote: >> Hi, kosaki-san. >> >> I read the previous threads now. It's rather late :(. >> >> I think it's rather awkward that sudden big change of order from 10 to 0. >> >> This problem causes zone_water_mark's fail. >> It mean now this zone's proportional free page per order size is not good. >> Although order-0 page is very important, Shouldn't we consider other >> order allocations ? >> >> So I want to balance zone's proportional free page. >> How about following ? >> >> if (nr_reclaimed < SWAP_CLUSTER_MAX) { >> if (order != 0) { >> order -=1; >> sc.order -=1; >> } >> } >> >> It prevents infinite loop and do best effort to make zone's >> proportional free page per order size good. >> >> It's just my opinion within my knowledge. >> If it have a problem, pz, explain me :) > > Please read Nick's expalin. it explain very kindly :) Hm. I read Nick's explain. I understand his point. Nick said, "A higher kswapd reclaim order shouldn't weaken kswapd postcondition for order-0 memory." My patch don't prevent order-0 memory reclaim. After all, it will do it. It also can do best effort to reclaim other order size. In this case, others order size reclaim is needless ? -- Kinds regards, MinChan Kim -- 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