From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261271AbVCHFpl (ORCPT ); Tue, 8 Mar 2005 00:45:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261448AbVCHFoV (ORCPT ); Tue, 8 Mar 2005 00:44:21 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:5829 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S261271AbVCHFn3 (ORCPT ); Tue, 8 Mar 2005 00:43:29 -0500 Date: Tue, 8 Mar 2005 05:43:25 +0000 From: Christoph Hellwig To: Andrew Morton Cc: Matt Mackall , linux-kernel@vger.kernel.org, viro@parcelfarce.linux.theplanet.co.uk Subject: Re: [PATCH] unified device list allocator Message-ID: <20050308054325.GA1262@infradead.org> Mail-Followup-To: Christoph Hellwig , Andrew Morton , Matt Mackall , linux-kernel@vger.kernel.org, viro@parcelfarce.linux.theplanet.co.uk References: <20050308051818.GI3120@waste.org> <20050307213302.560de053.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050307213302.560de053.akpm@osdl.org> User-Agent: Mutt/1.4.1i 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 On Mon, Mar 07, 2005 at 09:33:02PM -0800, Andrew Morton wrote: > Matt Mackall wrote: > > > > + /* search for insertion point in reverse for dynamic allocation */ > > + list_for_each_prev(l, list) { > > hrmph. Any time we do anything in O(n) time, some smarty comes along with > a workload which blows us out of the water. Although it's hard to think of > any register_blkdev()-intensive workloads. > > It's not possible to do this with prio-trees? Andrew, I think in this particular case you suffer of a sporadic severe condition of overengineeritis. register_blkdev only happens at module_init time (and in fact should go away completely, so I'm not happy wit hthe surgey to keep it barely alive at all)