From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id 6A6F960044A for ; Mon, 28 Dec 2009 04:59:32 -0500 (EST) Received: by pwi1 with SMTP id 1so7936691pwi.6 for ; Mon, 28 Dec 2009 01:59:31 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20091228144302.864f2e97.kamezawa.hiroyu@jp.fujitsu.com> References: <20091228134619.92ba28f6.minchan.kim@barrios-desktop> <20091228134752.44d13c34.kamezawa.hiroyu@jp.fujitsu.com> <20091228143154.ec0431b5.minchan.kim@barrios-desktop> <20091228144302.864f2e97.kamezawa.hiroyu@jp.fujitsu.com> Date: Mon, 28 Dec 2009 18:59:30 +0900 Message-ID: <28c262360912280159r69612770j97e30c3948c88c92@mail.gmail.com> Subject: Re: [PATCH -mmotm-2009-12-10-17-19] Fix wrong rss count of smaps From: Minchan Kim Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Andrew Morton , lkml , linux-mm , Matt Mackall , Hugh Dickins List-ID: On Mon, Dec 28, 2009 at 2:43 PM, KAMEZAWA Hiroyuki wrote: > On Mon, 28 Dec 2009 14:31:54 +0900 > Minchan Kim wrote: >> >> > BTW, how about counting ZERO page in smaps? Ignoring them completely sounds >> > not very good. >> >> I am not use it is useful. >> >> zero page snapshot of ongoing process is useful? >> Doesn't Admin need to know about zero page? >> Let's admins use it well. If we remove zero page again? >> How many are applications use smaps? >> Did we have a problem without it? >> > My concern is that hiding indormation which was exported before. > No more than that and no strong demand. > > >> When I think of it, there are too many qeustions. >> Most important thing to add new statistics is just need of customer. >> >> Frankly speaking, I don't have good scenario of using zero page. >> Do you have any scenario it is valueable? >> > read before write ? maybe sometimes happens. > > For example. current glibc's calloc() avoids memset() if the pages are > dropped by MADVISE (without unmap). > > Before starting zero-page works, I checked "questions" in lkml and > found some reports that some applications start to go OOM after zero-page > removal. > > For me, I know one of my customer's application depends on behavior of > zero page (on RHEL5). So, I tried to add again it before RHEL6 because > I think removal of zero-page corrupts compatibility. > Okay. I will repost the patch. > Thanks, > -Kame > > -- 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