From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758810AbcCVN4U (ORCPT ); Tue, 22 Mar 2016 09:56:20 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:6627 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753127AbcCVN4L (ORCPT ); Tue, 22 Mar 2016 09:56:11 -0400 Message-ID: <56F14EEE.7060308@huawei.com> Date: Tue, 22 Mar 2016 21:55:58 +0800 From: Xishi Qiu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Linux MM , LKML Subject: [RFC] mm: why cat /proc/pid/smaps | grep Rss is different from cat /proc/pid/statm? Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.25.179] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020206.56F14EF8.0008,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 574201e7640ab182f5042f2b5ca9a308 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [root@localhost c_test]# cat /proc/3948/smaps | grep Rss Rss: 4 kB Rss: 4 kB Rss: 4 kB Rss: 796 kB Rss: 0 kB Rss: 16 kB Rss: 8 kB Rss: 12 kB Rss: 132 kB Rss: 12 kB Rss: 4 kB Rss: 4 kB Rss: 4 kB Rss: 4 kB Rss: 12 kB Rss: 0 kB Rss: 4 kB Rss: 0 kB [root@localhost c_test]# cat /proc/3948/statm 1042 173 154 1 0 48 0 173 means Rss is 173*4kb=692kb, right? so why it is different from the sum(1020kb) of "cat /proc/pid/smaps | grep Rss"? my test code is ... int main() { sleep(1000); return 0; } the kernel version is v4.1 Thanks, Xishi Qiu