Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161225AbWJXUmn (ORCPT ); Tue, 24 Oct 2006 16:42:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161226AbWJXUmn (ORCPT ); Tue, 24 Oct 2006 16:42:43 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:59558 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S1161225AbWJXUmm (ORCPT ); Tue, 24 Oct 2006 16:42:42 -0400 Date: Tue, 24 Oct 2006 21:42:39 +0100 From: Christoph Hellwig To: Nigel Cunningham Cc: Andrew Morton , "Rafael J. Wysocki" , LKML Subject: Re: [PATCH] Use extents for recording what swap is allocated. Message-ID: <20061024204239.GA15689@infradead.org> Mail-Followup-To: Christoph Hellwig , Nigel Cunningham , Andrew Morton , "Rafael J. Wysocki" , LKML References: <1161576857.3466.9.camel@nigel.suspend2.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1161576857.3466.9.camel@nigel.suspend2.net> User-Agent: Mutt/1.4.2.1i X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1002 Lines: 21 On Mon, Oct 23, 2006 at 02:14:17PM +1000, Nigel Cunningham wrote: > Switch from bitmaps to using extents to record what swap is allocated; > they make more efficient use of memory, particularly where the allocated > storage is small and the swap space is large. > > This is also part of the ground work for implementing support for > supporting multiple swap devices. In addition to the very useful comments from Rafael there's some observations of my own: - there's an awful lot of opencoded list manipulation, any chance you could use list.h instead? - what unit are the extent values in? The usage of unsigned long rings warning bells for me, shouldn't this be something like pgoff_t or sector_t depending on what you describe with it? - 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/