From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754200AbaCCJRA (ORCPT ); Mon, 3 Mar 2014 04:17:00 -0500 Received: from merlin.infradead.org ([205.233.59.134]:32895 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754099AbaCCJQ6 (ORCPT ); Mon, 3 Mar 2014 04:16:58 -0500 Date: Mon, 3 Mar 2014 10:16:37 +0100 From: Peter Zijlstra To: Ingo Molnar Cc: Steven Rostedt , "H. Peter Anvin" , Vince Weaver , Linux Kernel , Ingo Molnar , Jiri Olsa , Arnaldo Carvalho de Melo Subject: Re: perf_fuzzer compiled for x32 causes reboot Message-ID: <20140303091637.GO27965@twins.programming.kicks-ass.net> References: <20140228092341.12a40f7c@gandalf.local.home> <1c583986-74f8-4829-883b-390dc49ddabb@email.android.com> <20140228154026.GH9987@twins.programming.kicks-ass.net> <5310B60F.30806@zytor.com> <20140228112946.1f194397@gandalf.local.home> <20140228205638.GD14089@laptop.programming.kicks-ass.net> <20140228160638.3b045dbc@gandalf.local.home> <20140301091650.GD5885@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140301091650.GD5885@gmail.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Mar 01, 2014 at 10:16:50AM +0100, Ingo Molnar wrote: > We read CR2 in the page fault hot path, so it's on the top of CPU > architects' minds and it's reasonably optimized. A couple of cycles > IIRC, but would be nice to hear actual numbers. Well, going with what Linus found; it looks like they made page faults more expensive on Haswell as compared to previous generations. So its not _that_ high on their list :/