From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964918AbWJWPe3 (ORCPT ); Mon, 23 Oct 2006 11:34:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964956AbWJWPe3 (ORCPT ); Mon, 23 Oct 2006 11:34:29 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:43405 "EHLO amd.ucw.cz") by vger.kernel.org with ESMTP id S964918AbWJWPe2 (ORCPT ); Mon, 23 Oct 2006 11:34:28 -0400 Date: Mon, 23 Oct 2006 17:32:57 +0200 From: Pavel Machek To: Nigel Cunningham Cc: Andrew Morton , "Rafael J. Wysocki" , LKML Subject: Re: [PATCH] Use extents for recording what swap is allocated. Message-ID: <20061023153257.GC8414@elf.ucw.cz> 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> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.11+cvs20060126 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! > 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. bitmaps were more efficient and longer than original code... I did not _like_ them, but they are in now. I'd hate to change the code again, for what, 0.5% gain? ...and this is still longer than bitmaps. And SNAPSHOT_GET_SWAP_PAGE seems to support multiple swap spaces already. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html