Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 24 Jul 2001 13:53:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 24 Jul 2001 13:53:03 -0400 Received: from perninha.conectiva.com.br ([200.250.58.156]:27153 "HELO perninha.conectiva.com.br") by vger.kernel.org with SMTP id ; Tue, 24 Jul 2001 13:52:53 -0400 Date: Tue, 24 Jul 2001 14:52:50 -0300 (BRST) From: Rik van Riel X-X-Sender: To: Mike Castle Cc: Subject: Re: [RFC] Optimization for use-once pages In-Reply-To: <20010724104453.G5835@thune.mrc-home.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Original-Recipient: rfc822;linux-kernel-outgoing On Tue, 24 Jul 2001, Mike Castle wrote: > On Tue, Jul 24, 2001 at 02:07:32PM -0300, Rik van Riel wrote: > > > I hate to bother you directly, but I don't wish to start a flame > > > war on lkml. How exactly would you explain two accesses as > > > being "used once"? > > > > Because they occur in a very short interval, an interval MUCH > > shorter than the time scale in which the VM subsystem looks at > > referenced bits, etc... > > Would mmap() then a for(;;) loop over the range be an example of > such a use? Yes. The problem here, however, would be that we'll only find the referenced bit in the page table some time later. This is another reason for having a "new" queue like 2Q's A1in queue. It means we can both count all accesses in the first short period as one access AND we can avoid actually doing anything special as these accesses happen.... regards, Rik -- Executive summary of a recent Microsoft press release: "we are concerned about the GNU General Public License (GPL)" http://www.surriel.com/ http://www.conectiva.com/ http://distro.conectiva.com/ - 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/