From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754675AbYHVPZ0 (ORCPT ); Fri, 22 Aug 2008 11:25:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751101AbYHVPZN (ORCPT ); Fri, 22 Aug 2008 11:25:13 -0400 Received: from mx.bridgeco.net ([213.173.191.47]:3086 "EHLO mx.bridgeco.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751574AbYHVPZM convert rfc822-to-8bit (ORCPT ); Fri, 22 Aug 2008 11:25:12 -0400 X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Subject: RE: Behaviour of the VM on a embedded linux Date: Fri, 22 Aug 2008 17:25:10 +0200 Message-ID: <83116F0A4FF67A4F97BA0B6E408C48E30289D979@zuerich.BC-Int.NET> In-Reply-To: <81b0412b0808220559w502edf03y7f318d0f3673884@mail.gmail.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: Behaviour of the VM on a embedded linux Thread-Index: AckEVvPbIxtwFNJqQbCjbn3fwarS3gAE6oyA References: <83116F0A4FF67A4F97BA0B6E408C48E30289D8F0@zuerich.BC-Int.NET> <81b0412b0808220559w502edf03y7f318d0f3673884@mail.gmail.com> From: "Wappler Marcel" To: "Alex Riesen" Cc: X-OriginalArrivalTime: 22 Aug 2008 15:24:48.0981 (UTC) FILETIME=[3722D050:01C9046B] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alex Riesen wrote: >> I'm trying to figure out whats going on an embedded system I have to >> deal with. It's running a 2.6.24.7 kernel on 32 MBytes of RAM. >> There is no swapping. There are some daemons and shells running and >> - a big monolithic c++ application. >> >> The application runs a lot of pthreads on different real time >> priority levels. It looks like the application consumes a huge >> ammount of real memory >> in contrast to the assumption, that large code size is no problem due >> to paging out pages with unused code. > > Maybe the kernel wont page anything if the paging support is compiled > out. IOW, you still need paging code even if there is now swap > partitions. Alex, this is the case - I do observe normal operation of the VM subsytem - it moves memory pages dynamicaly throughout the system. But: when I create a large file on the tmpfs a kernel OOM occurs and kills the big monolithic application instead of stealing pages from the application. This is the fact I'm wondering about. In the past every guy told me that code size is no problem on systems using MMUs because the system can steal pages which contain code of the application in situations of low memory. But in my situation this is not the case. Any ideas? Marcel PS: please CC me on replies