From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030833AbWKOSvE (ORCPT ); Wed, 15 Nov 2006 13:51:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030868AbWKOSvE (ORCPT ); Wed, 15 Nov 2006 13:51:04 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:32735 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S1030838AbWKOSvB (ORCPT ); Wed, 15 Nov 2006 13:51:01 -0500 Date: Wed, 15 Nov 2006 19:49:36 +0100 From: Ingo Molnar To: Jeremy Fitzhardinge Cc: Arjan van de Ven , akpm@osdl.org, ak@suse.de, linux-kernel@vger.kernel.org, Michael.Fetterman@cl.cam.ac.uk, Ian Campbell Subject: Re: i386 PDA patches use of %gs Message-ID: <20061115184936.GA6389@elte.hu> References: <1158046540.2992.5.camel@laptopd505.fenrus.org> <45075829.701@goop.org> <20060913095942.GA10075@elte.hu> <45082F1C.8000003@goop.org> <20061115182613.GA2227@elte.hu> <455B5ED8.5090005@goop.org> <20061115184315.GA5078@elte.hu> <455B611C.3010503@goop.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <455B611C.3010503@goop.org> User-Agent: Mutt/1.4.2.2i X-ELTE-SpamScore: -4.4 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-4.4 required=5.9 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=no SpamAssassin version=3.0.3 -3.3 ALL_TRUSTED Did not pass through any untrusted hosts -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] 1.5 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Jeremy Fitzhardinge wrote: > Ingo Molnar wrote: > > but it does not actually use the 'normal usermode TLS selector' - it > > only loads it. > > > > a meaningful test would be to allocate two selector values and load and > > read+write memory through both of them. > > > > Well, obviously in one case it would need to switch between > null/non-null/null. But yes, good point about using the "usermode" > %gs each iteration. I'll do some more tests. i'd not even use glibc's %gs but set up two separate selectors. (that's a more controlled experiment - someone might run a non-TLS glibc, etc.) Ingo