Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932265AbWIRTBG (ORCPT ); Mon, 18 Sep 2006 15:01:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932272AbWIRTBG (ORCPT ); Mon, 18 Sep 2006 15:01:06 -0400 Received: from gw.goop.org ([64.81.55.164]:59309 "EHLO mail.goop.org") by vger.kernel.org with ESMTP id S932265AbWIRTBE (ORCPT ); Mon, 18 Sep 2006 15:01:04 -0400 Message-ID: <450EECEC.207@goop.org> Date: Mon, 18 Sep 2006 12:01:00 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 1.5.0.7 (X11/20060913) MIME-Version: 1.0 To: Andi Kleen CC: Benjamin LaHaise , Linus Torvalds , Andrew Morton , Chuck Ebbert <76306.1226@compuserve.com>, In Cognito , linux-kernel , Ingo Molnar Subject: Re: Sysenter crash with Nested Task Bit set References: <200609172354_MC3-1-CB7A-58ED@compuserve.com> <200609181729.23934.ak@suse.de> <20060918161251.GC19815@kvack.org> <200609181839.45546.ak@suse.de> In-Reply-To: <200609181839.45546.ak@suse.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 577 Lines: 15 Andi Kleen wrote: > Yes it's never fast, but on basically all non P4 CPUs it is still fast enough > to not be a problem. I suppose it causes a trace cache flush or something like > that there. I don't think it's that bad, but it might cause a full pipeline flush. I seem to remember measuring its cost at about 50 cycles. J - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/