Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262499AbVAKHqE (ORCPT ); Tue, 11 Jan 2005 02:46:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262477AbVAKHoH (ORCPT ); Tue, 11 Jan 2005 02:44:07 -0500 Received: from canuck.infradead.org ([205.233.218.70]:24582 "EHLO canuck.infradead.org") by vger.kernel.org with ESMTP id S262498AbVAKHms (ORCPT ); Tue, 11 Jan 2005 02:42:48 -0500 Subject: Re: address space reservation functionality? From: Arjan van de Ven To: "Robert W. Fuller" Cc: Linux Kernel Mailing List In-Reply-To: <41E2EB09.5000603@sbcglobal.net> References: <41E2EB09.5000603@sbcglobal.net> Content-Type: text/plain Date: Tue, 11 Jan 2005 08:42:42 +0100 Message-Id: <1105429362.3917.2.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.0.2 (2.0.2-3) Content-Transfer-Encoding: 7bit X-Spam-Score: 4.1 (++++) X-Spam-Report: SpamAssassin version 2.63 on canuck.infradead.org summary: Content analysis details: (4.1 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.3 RCVD_NUMERIC_HELO Received: contains a numeric HELO 1.1 RCVD_IN_DSBL RBL: Received via a relay in list.dsbl.org [] 2.5 RCVD_IN_DYNABLOCK RBL: Sent directly from dynamic IP address [80.57.133.107 listed in dnsbl.sorbs.net] 0.1 RCVD_IN_SORBS RBL: SORBS: sender is listed in SORBS [80.57.133.107 listed in dnsbl.sorbs.net] X-SRS-Rewrite: SMTP reverse-path rewritten from by canuck.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1152 Lines: 23 On Mon, 2005-01-10 at 15:52 -0500, Robert W. Fuller wrote: > Hi, > > I was wondering if some functionality existed in Linux. Specifically, > in Solaris, you can mmap the null device in order to reserve part of the > address space without otherwise consuming resources. This is detailed > in the Solaris manpage null(7D). The same functionality is also > available under Windows NT/XP/2K by calling the VirtualAlloc function > with the MEM_RESERVE flag omitting the MEM_COMMIT flag. Does Linux have > a similar mechanism buried somewhere whereby I can reserve a part of the > address space and not increase the "virtual size" of the process or the > system's idea of the amount of memory in use? I could not find one by > using the source. malloc() already does this... what you describe is the default behavior of linux; only when you actually write to the memory does it get backed by ram. - 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/