Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756707Ab2K0S3N (ORCPT ); Tue, 27 Nov 2012 13:29:13 -0500 Received: from plane.gmane.org ([80.91.229.3]:57506 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755961Ab2K0S3L (ORCPT ); Tue, 27 Nov 2012 13:29:11 -0500 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: Bernd Schubert Subject: memory allocation: smap large "Size", but unused Date: Tue, 27 Nov 2012 19:28:52 +0100 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: tc-gate1.pci.uni-heidelberg.de User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1028 Lines: 29 Hello, I'm just investigating why a user space program has a rather large VmSize, but small VmRSS size. Looking into /proc/$pid/smaps I notice several areas with an size of about 64MB, but otherwise that area is unused. So far I did not find a way how to reproduce that with malloc() calls. 7ffd34021000-7ffd38000000 ---p 00000000 00:00 0 Size: 65404 kB Rss: 0 kB Pss: 0 kB Shared_Clean: 0 kB Shared_Dirty: 0 kB Private_Clean: 0 kB Private_Dirty: 0 kB Referenced: 0 kB Anonymous: 0 kB AnonHugePages: 0 kB Swap: 0 kB KernelPageSize: 4 kB MMUPageSize: 4 kB Any idea how to do such an allocation from user space? Thanks, Bernd -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/