From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754579Ab1KTXbU (ORCPT ); Sun, 20 Nov 2011 18:31:20 -0500 Received: from terminus.zytor.com ([198.137.202.10]:43049 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754199Ab1KTXbR (ORCPT ); Sun, 20 Nov 2011 18:31:17 -0500 Message-ID: <4EC98DB3.1090008@kernel.org> Date: Sun, 20 Nov 2011 15:30:59 -0800 From: "H. Peter Anvin" Organization: Linux Kernel Organization, Inc. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0.1) Gecko/20110930 Thunderbird/7.0.1 MIME-Version: 1.0 To: David Woodhouse CC: David Daney , linux-mips@linux-mips.org, ralf@linux-mips.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-embedded@vger.kernel.org, x86@kernel.org, David Daney Subject: Re: [PATCH RFC 1/5] scripts: Add sortextable to sort the kernel's exception table. References: <1321645068-20475-1-git-send-email-ddaney.cavm@gmail.com> <1321645068-20475-2-git-send-email-ddaney.cavm@gmail.com> <4EC98C97.50604@kernel.org> <1321831713.15493.87.camel@shinybook.infradead.org> In-Reply-To: <1321831713.15493.87.camel@shinybook.infradead.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/20/2011 03:28 PM, David Woodhouse wrote: > On Sun, 2011-11-20 at 15:26 -0800, H. Peter Anvin wrote: >> If we're going to do this at build time, I would suggest using a >> collisionless hash instead. The lookup time for those are O(1), but >> they definitely need to be done at build time. > > Is the lookup time really an issue? > Probably not a big one (in most scenarios), but with better exception handling it might stretch the usability of exceptions. The bigger thing is that once you're doing a build-time special handler for this *anyway*, you might as well drive the cost of the lookup to functionally zero. -hpa