From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.12] helo=sc8-sf-mx2.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1Alh6u-0006TH-Vp for user-mode-linux-devel@lists.sourceforge.net; Tue, 27 Jan 2004 20:15:28 -0800 Received: from [12.177.129.25] (helo=ccure.user-mode-linux.org) by sc8-sf-mx2.sourceforge.net with esmtp (TLSv1:DES-CBC3-SHA:168) (Exim 4.30) id 1Alh6u-0002En-Ey for user-mode-linux-devel@lists.sourceforge.net; Tue, 27 Jan 2004 20:15:28 -0800 Message-Id: <200401280439.i0S4dMZw005517@ccure.user-mode-linux.org> Subject: Re: [uml-devel] Swapping directly to host swap area? In-Reply-To: Your message of "Sun, 25 Jan 2004 18:34:12 EST." References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii From: Jeff Dike Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Tue, 27 Jan 2004 23:39:22 -0500 To: William Stearns Cc: ML-uml-devel wstearns@pobox.com said: > When a VM needs to swap out, is there some way the UML kernel could > send that sector directly to the host swap area instead of running its > own swap? No, but this isn't the real question. > In the current setup, the host kernel sees this as a normal > write to an open file, caching it in the process and so not truly > freeing up the ram for a bit. This is, and this could be done by setting O_DIRECT on UML swap devices. That way, writes go directly (and asynchronously) to the device without landing in the cache. With mmap in effect, this can also be done with a MADVISE_DONTNEED on the relevant pages of the swap file. Patches cheerfully accepted. Jeff ------------------------------------------------------- The SF.Net email is sponsored by EclipseCon 2004 Premiere Conference on Open Tools Development and Integration See the breadth of Eclipse activity. February 3-5 in Anaheim, CA. http://www.eclipsecon.org/osdn _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel