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, 28 Jul 2002 21:34:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 28 Jul 2002 21:34:01 -0400 Received: from holomorphy.com ([66.224.33.161]:25770 "EHLO holomorphy") by vger.kernel.org with ESMTP id ; Sun, 28 Jul 2002 21:34:01 -0400 Date: Sun, 28 Jul 2002 18:37:02 -0700 From: William Lee Irwin III To: Andrew Morton Cc: Linux Kernel Subject: Re: [BK PATCH 2.5] Introduce 64-bit versions of PAGE_{CACHE_,}{MASK,ALIGN} Message-ID: <20020729013702.GV25038@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Andrew Morton , Linux Kernel References: <5.1.0.14.2.20020728193528.04336a80@pop.cus.cam.ac.uk> <3D448808.CF8D18BA@zip.com.au> <20020729005649.GT25038@holomorphy.com> <3D449C14.46683B2A@zip.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Description: brief message Content-Disposition: inline In-Reply-To: <3D449C14.46683B2A@zip.com.au> User-Agent: Mutt/1.3.25i Organization: The Domain of Holomorphy Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org William Lee Irwin III wrote: >> Do you know an approximate reasonable constant of proportionality >> for how many pages have ->private attached? On Sun, Jul 28, 2002 at 06:36:20PM -0700, Andrew Morton wrote: > Well, it depends on what the mapping is using ->private for. > In the case of ext2, ext3 and (soon) reiserfs mappings, ->private > is only used for pagecache pages which were written to with write(2). > But for other filesystems, basically all pagecache pages have > buffers at present, so I exaggerate. But as filesystems migrate > to using direct-to-BIO reads, the situation gets better. > It might be useful to buffer-strip written-to pages as well, if > a clean way of doing that presents itself. Maybe in refill_inactive > or something. Collecting some numbers might be useful here. On Sun, Jul 28, 2002 at 05:10:48PM -0700, Andrew Morton wrote: >>> - Remove the rmap chain (I just broke ptep_to_address() anyway). 4 bytes >>> saved. struct page is now 20 bytes. William Lee Irwin III wrote: >> How did ptep_to_address() break? I browsed over your latest changes and >> missed the bit where that fell apart. I'll at least take a stab at fixing >> it up until the other bits materialize. On Sun, Jul 28, 2002 at 06:36:20PM -0700, Andrew Morton wrote: > I broke it in my five-minute thought-coding exercise. By removing > page->index. Sorry, I took fixing up the users as part of the ->index removal. This isn't a serious issue. Cheers, Bill