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 13E31600068 for ; Sun, 3 Jan 2010 19:49:47 -0500 (EST) Received: by pxi5 with SMTP id 5so10100625pxi.12 for ; Sun, 03 Jan 2010 16:49:46 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: <4B38876F.6010204@gmail.com> <28c262360912301841r3ed43d31yc677fbc3a01fe5bb@mail.gmail.com> Date: Mon, 4 Jan 2010 09:49:46 +0900 Message-ID: <28c262361001031649w60a59151m8e210304217d4e35@mail.gmail.com> Subject: Re: [PATCH 2/3 -mmotm-2009-12-10-17-19] Count zero page as file_rss From: Minchan Kim Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org To: Hugh Dickins Cc: Andrew Morton , LKML , linux-mm , KAMEZAWA Hiroyuki List-ID: On Thu, Dec 31, 2009 at 5:43 PM, Hugh Dickins wrote: > On Thu, 31 Dec 2009, Minchan Kim wrote: >> On Thu, Dec 31, 2009 at 1:49 AM, Hugh Dickins >> wrote: >> > >> > You are right that I completely overlooked the issue of whether to >> > include the ZERO_PAGE in rss counts (now being a !vm_normal_page, >> > it was just natural to leave it out); and I overlooked the fact that >> > it used to be counted into file_rss in the old days (being !PageAnon). >> > >> > So I'm certainly at fault for that, and thank you for bringing the >> > issue to attention; but once considered, I can't actually see a good >> > reason why we should add code to count ZERO_PAGEs into file_rss now. >> > And if this patch falls, then 1/3 and 3/3 would fall also. >> > >> > And the patch below would be incomplete anyway, wouldn't it? >> > There would need to be a matching change to zap_pte_range(), >> > but I don't see that. >> >> Thanks. >> If we think this patch is need, I will repost path with fix it. >> >> What do you think? > > If someone comes up with a convincing case in which their system > is behaving significantly worse because the zero page is not being > counted in rss now, then we shall probably want your patch. > But I still don't yet see a reason to add code just to keep the > anon_rss+file_rss number looking the same as it was before, in this > exceptional case where there's a significant number of zero pages. Okay. I understand your point. I will repost this patch when we need this. :) Thanks for careful review, Hugh. > > Hugh > -- Kind 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