From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754094AbaCCMbX (ORCPT ); Mon, 3 Mar 2014 07:31:23 -0500 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:48703 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753360AbaCCMbW (ORCPT ); Mon, 3 Mar 2014 07:31:22 -0500 Date: Mon, 3 Mar 2014 12:31:06 +0000 From: One Thousand Gnomes To: Gene Heskett Cc: Dave Jones , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86: set Pentium M as PAE capable Message-ID: <20140303123106.15f7b424@alan.etchedpixels.co.uk> In-Reply-To: <201403021642.33087.gheskett@wdtv.com> References: <20140228140043.GA12157@debian.local> <20140302205619.GA8676@rhlx01.hs-esslingen.de> <20140302210201.GA31948@redhat.com> <201403021642.33087.gheskett@wdtv.com> Organization: Intel Corporation X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.20; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > We routinely expect 2 to 3 u-s jitters on an Atom board running a 32 bit, > RTAI enhanced build of what is by now a 5 year old kernel. This is > extremely board sensitive, and that same kernel running on this 4 core > phenom, cannot stay inside of 40 u-s. A case of more horsepower not being > a good deal at all. Can't speak for AMD devices but I would be curious to know more on the Intel side about this and how you measured and analysed it. Are you running with any hyperthreading disabled, a firmware which is not using SMM, and with any critical code pinned in cache ? How do you have power management set up ? (probably best taken off list) Alan