From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [discuss] Re: [PATCH] Allow all Opteron processors to change pstate at same time Date: Wed, 12 Jul 2006 16:54:54 +0200 Message-ID: <200607121654.54152.ak@suse.de> References: <1152622554.4489.32.camel@lapdog.site> <1152713168.14450.18.camel@lapdog.site> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1152713168.14450.18.camel@lapdog.site> Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-Id: Content-Type: text/plain; charset="us-ascii" To: discuss@x86-64.org Cc: Joachim Deguara , Mark Langsdorf , linux-kernel@vger.kernel.org, cpufreq@lists.linux.org.uk On Wednesday 12 July 2006 16:06, Joachim Deguara wrote: > On Tue, 2006-07-11 at 14:55 +0200, Joachim Deguara wrote: > > Here are some initial findings. > > Here are the further findings after letting the machine toggle between > 1GHz and 2.2Ghz every two seconds for roughly 24 hours. Unfortunately > there is an oops after bringing CPU2 online and CPU3 will not come > online. Perhaps Mark/Jacob can take a look at the oops. > Still the differences in TSC are not bad: Think: any difference you get for 24h will be 10x when the system runs 10 times longer and 365 times when the system runs for a year (and there are Linux systems who run much longer than a year) Also even small non monotonies between CPUs in gettimeofday can cause big trouble. -Andi