Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261539AbVEOHat (ORCPT ); Sun, 15 May 2005 03:30:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261544AbVEOHat (ORCPT ); Sun, 15 May 2005 03:30:49 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:33423 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S261539AbVEOHao (ORCPT ); Sun, 15 May 2005 03:30:44 -0400 Subject: Re: Hyper-Threading Vulnerability From: Arjan van de Ven To: Lee Revell Cc: Alan Cox , Dave Jones , Matt Mackall , Andy Isaacson , Andi Kleen , "Richard F. Rebel" , Gabor MICSKO , Linux Kernel Mailing List , tytso@mit.edu In-Reply-To: <1116114052.9141.38.camel@mindpipe> References: <1115963481.1723.3.camel@alderaan.trey.hu> <1116009483.4689.803.camel@rebel.corp.whenu.com> <20050513190549.GB47131@muc.de> <20050513212620.GA12522@hexapodia.org> <20050513215905.GY5914@waste.org> <1116024419.20646.41.camel@localhost.localdomain> <1116025212.6380.50.camel@mindpipe> <20050513232708.GC13846@redhat.com> <1116027488.6380.55.camel@mindpipe> <1116084186.20545.47.camel@localhost.localdomain> <1116088229.8880.7.camel@mindpipe> <1116089068.6007.13.camel@laptopd505.fenrus.org> <1116093396.9141.11.camel@mindpipe> <1116093694.6007.15.camel@laptopd505.fenrus.org> <1116098504.9141.31.camel@mindpipe> <1116100126.6007.17.camel@laptopd505.fenrus.org> <1116114052.9141.38.camel@mindpipe> Content-Type: text/plain Date: Sun, 15 May 2005 09:30:33 +0200 Message-Id: <1116142233.6270.9.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 (2.0.4-4) Content-Transfer-Encoding: 7bit X-Spam-Score: 3.7 (+++) X-Spam-Report: SpamAssassin version 2.63 on pentafluge.infradead.org summary: Content analysis details: (3.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 1.1 RCVD_IN_DSBL RBL: Received via a relay in list.dsbl.org [] 2.5 RCVD_IN_DYNABLOCK RBL: Sent directly from dynamic IP address [80.57.133.107 listed in dnsbl.sorbs.net] 0.1 RCVD_IN_SORBS RBL: SORBS: sender is listed in SORBS [80.57.133.107 listed in dnsbl.sorbs.net] X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 970 Lines: 21 On Sat, 2005-05-14 at 19:40 -0400, Lee Revell wrote: > > it's a matter of time (my estimate is a year or two) before processors > > get variable frequencies based on temperature targets etc... > > and then rdtsc is really useless for this kind of thing.. > > I was under the impression that P4 and later processors do not vary the > TSC rate when doing frequency scaling. This is mentioned in the > documentation for the high res timers patch. seems not the case, and worse, during idle time the clock is allowed to stop entirely.... (and that is also happening more and more and linux is getting more agressive idle support (eg no timer tick and such patches) which will trigger bios thresholds for this even more too. - 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/