Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 6 Mar 2002 12:07:02 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 6 Mar 2002 12:06:56 -0500 Received: from mnh-1-27.mv.com ([207.22.10.59]:10759 "EHLO ccure.karaya.com") by vger.kernel.org with ESMTP id ; Wed, 6 Mar 2002 12:06:20 -0500 Message-Id: <200203061708.MAA02691@ccure.karaya.com> X-Mailer: exmh version 2.0.2 To: Jesse Pollard cc: linux-kernel@vger.kernel.org Subject: Re: [RFC] Arch option to touch newly allocated pages In-Reply-To: Your message of "Wed, 06 Mar 2002 10:03:57 CST." <200203061603.KAA21855@tomcat.admin.navo.hpc.mil> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 06 Mar 2002 12:08:09 -0500 From: Jeff Dike Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org pollard@tomcat.admin.navo.hpc.mil said: > Currently the only way to ensure that the memory IS available is to > modify every page at startup. Yes it will swap the modified pages. Currently, yes. But with Alan says his address space accounting will prevent mmaps from succeeding if populating them would OOM the system, which gives you want you want and which sounds like the right thing. The 8 64M UMLs will run without needing to touch all their pages at bootup and without fear of being killed later. If the 9th UML would be in danger of random death, then it will never get off the ground. Note that this doesn't help when the UMLs are under a smaller limit than RAM + .5 * swap or whatever as happens when they are mmapping from tmpfs. That's the situation that I'm concerned about. Jeff - 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/