Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 31 Jul 2001 09:42:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 31 Jul 2001 09:42:25 -0400 Received: from fm4.freemail.hu ([194.38.105.14]:25862 "HELO fm4.freemail.hu") by vger.kernel.org with SMTP id ; Tue, 31 Jul 2001 09:42:11 -0400 Date: Tue, 31 Jul 2001 15:42:04 +0200 (CEST) From: Boszormenyi Zoltan Subject: used-once really works? To: linux-kernel@vger.kernel.org Message-ID: X-Originating-IP: [212.40.102.60] X-HTTP-User-Agent: Mozilla/5.0 (X11; U; Linux 2.4.8-pre3 i686; en-US; rv:0.9.1) Gecko/20010620 MIME-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=ISO-8859-2 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Original-Recipient: rfc822;linux-kernel-outgoing Hi! I freshly compiled 2.4.8-pre3 and I thought I give it a try. The machine is a dual P3 with 384MB memory and one 15 GB IDE disk, distro is RedHat 6.2 with official upgrades and e2fsprogs-1.22 and GNOME-1.4. In X, I had mozilla, and 3 gnome-terminals running. In one terminal, I run 'top', in one other 'dd if=/dev/hda of=/dev/null bs=4096'. 'top' showed that the system buffer cache filled up and soon the machine started swapping. It seemed to swap out mozilla and parts of the X server. Otherwise the system remained responsive. I tried other more experimental patches, too: o_direct-10 and blkdev-pagecache-5. There was a one-liner reject in mm/vmscan.c after applying blkdev-pagecache-5. I fixed this and booted this new kernel, I tried the same. This time the page cache started to fill up but no swapping occured. Hm... During 'dd' starting new (I mean: not yet in the page cache) programs were slow as hell. Starting them second time was fast as expected. I tried glade with a large project file, loading it / looking into directories was slow at first, was fast second time. Since ext2 directories are in the page cache, this is perfectly understandable. So it seems that the used-once patch works. The only comments is that I didn't expect it to start swapping with the stock pre3. I supposed it frees the "used-once" pages more quickly. Anyway I am not a VM expert and don't flame me about my non relevant comments. 2.4.8 seems promising :-) Regards, Zoltan Boszormenyi - 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/