From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932775Ab2DSWQ0 (ORCPT ); Thu, 19 Apr 2012 18:16:26 -0400 Received: from terminus.zytor.com ([198.137.202.10]:52023 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932620Ab2DSWQY (ORCPT ); Thu, 19 Apr 2012 18:16:24 -0400 Message-ID: <4F908EA5.4060507@zytor.com> Date: Thu, 19 Apr 2012 15:16:05 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120329 Thunderbird/11.0.1 MIME-Version: 1.0 To: David Daney CC: Linus Torvalds , Borislav Petkov , Linux Kernel Mailing List , Ingo Molnar , Thomas Gleixner , David Daney Subject: Re: [PATCH 3/3] x86, extable: Handle early exceptions References: <1334794610-5546-1-git-send-email-hpa@zytor.com> <20120419092255.GA29542@aftab> <20120419092630.GD29542@aftab> <4F904541.2030200@zytor.com> <20120419173802.GI3221@aftab.osrc.amd.com> <4F90527B.7020005@zytor.com> <9ff2e09c-57e4-455e-8614-1b3b17b652f4@email.android.com> <4F9072CA.6030903@gmail.com> In-Reply-To: <4F9072CA.6030903@gmail.com> X-Enigmail-Version: 1.4 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 04/19/2012 01:17 PM, David Daney wrote: > > I usually see exception table sizes on the order of 2^10 entries, so I > have to wonder how much you really gain from an O(1) implementation. > One thing that probably would give more of a boost is to use a rbtree or similar structure to figure out *which* extable (if any) we should be looking at; right now it looks like we linearly walk the modules, and don't even look to see if we are inside that module before we do a bsearch in that module's extable... -hpa