From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 26 Aug 2001 01:26:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 26 Aug 2001 01:26:05 -0400 Received: from humbolt.nl.linux.org ([131.211.28.48]:2317 "EHLO humbolt.nl.linux.org") by vger.kernel.org with ESMTP id ; Sun, 26 Aug 2001 01:25:50 -0400 Content-Type: text/plain; charset=US-ASCII From: Daniel Phillips To: Rik van Riel , John Stoffel Subject: Re: [resent PATCH] Re: very slow parallel read performance Date: Sun, 26 Aug 2001 07:28:03 +0200 X-Mailer: KMail [version 1.3.1] Cc: "Marc A. Lehmann" , Alan Cox , Roger Larsson , In-Reply-To: In-Reply-To: MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Message-Id: <20010826052500Z16213-32383+1412@humbolt.nl.linux.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On August 26, 2001 05:40 am, Rik van Riel wrote: > On Sat, 25 Aug 2001, John Stoffel wrote: > > > Ummm... is this really more of an agreement that Daniel's used-once > > patch is a good idea on a system. Keep a page around if it's used > > once, but drop it quickly if only used once? > > There's a very big difference, though. With use-once we'll > also quickly drop the pages we have not yet used, that is, > the pages we _are about to use_. You're really complaining about the treatment of readahead pages, not the used-once pages. We can arrange things so that readahead pages get higher priority than used-once pages, then become used-once pages when... they get used once. Simple idea, but not a one-line implementation. > Drop-behind specifically drops the pages we have already > used, giving better protection to the pages we are about > to use. > > http://linux-mm.org/wiki/moin.cgi/StreamingIo How will you know not to drop the pages of that header file that is used constantly by the compiler? -- Daniel