From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 66B7660021B for ; Mon, 28 Dec 2009 00:46:20 -0500 (EST) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id nBS5kGTf006531 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Mon, 28 Dec 2009 14:46:17 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 9154745DE69 for ; Mon, 28 Dec 2009 14:46:16 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 6357745DE66 for ; Mon, 28 Dec 2009 14:46:16 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 3B6951DB803C for ; Mon, 28 Dec 2009 14:46:16 +0900 (JST) Received: from m108.s.css.fujitsu.com (m108.s.css.fujitsu.com [10.249.87.108]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 62A521DB8041 for ; Mon, 28 Dec 2009 14:46:15 +0900 (JST) Date: Mon, 28 Dec 2009 14:43:02 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH -mmotm-2009-12-10-17-19] Fix wrong rss count of smaps Message-Id: <20091228144302.864f2e97.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20091228143154.ec0431b5.minchan.kim@barrios-desktop> References: <20091228134619.92ba28f6.minchan.kim@barrios-desktop> <20091228134752.44d13c34.kamezawa.hiroyu@jp.fujitsu.com> <20091228143154.ec0431b5.minchan.kim@barrios-desktop> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Minchan Kim Cc: Andrew Morton , lkml , linux-mm , Matt Mackall , Hugh Dickins List-ID: 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. Thanks, -Kame -- 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