From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262422AbVF2SkW (ORCPT ); Wed, 29 Jun 2005 14:40:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262419AbVF2Shr (ORCPT ); Wed, 29 Jun 2005 14:37:47 -0400 Received: from station-6.events.itd.umich.edu ([141.211.252.135]:8375 "EHLO amd.ucw.cz") by vger.kernel.org with ESMTP id S262411AbVF2Sg5 (ORCPT ); Wed, 29 Jun 2005 14:36:57 -0400 Date: Wed, 29 Jun 2005 18:31:00 +0200 From: Pavel Machek To: Nick Piggin Cc: Andy Whitcroft , linux-kernel , Linux Memory Management Subject: Re: [patch 2] mm: speculative get_page Message-ID: <20050629163100.GA13336@elf.ucw.cz> References: <42BF9CD1.2030102@yahoo.com.au> <42BF9D67.10509@yahoo.com.au> <42BF9D86.90204@yahoo.com.au> <42C14662.40809@shadowen.org> <42C14D93.7090303@yahoo.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <42C14D93.7090303@yahoo.com.au> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! > >There are a couple of bits which imply ownership such as PG_slab, > >PG_swapcache and PG_reserved which to my mind are all exclusive. > >Perhaps those plus the PG_free could be combined into a owner field. I > >am unsure if the PG_freeing can be 'backed out' if not it may also combine? > > I think there are a a few ways that bits can be reclaimed if we > start digging. swsusp uses 2 which seems excessive though may be > fully justified. Can PG_private be replaced by (!page->private)? > Can filesystems easily stop using PG_checked? It is possible that swsusp could reduce its bit usage... Current stuff works, but probably does not need strong atomicity guarantees, and could use some bit combination... Pavel -- teflon -- maybe it is a trademark, but it should not be.