From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756218Ab3JRPgy (ORCPT ); Fri, 18 Oct 2013 11:36:54 -0400 Received: from mail.skyhub.de ([78.46.96.112]:56054 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753998Ab3JRPgx (ORCPT ); Fri, 18 Oct 2013 11:36:53 -0400 Date: Fri, 18 Oct 2013 17:36:50 +0200 From: Borislav Petkov To: Joonas Saarinen Cc: linux-kernel@vger.kernel.org Subject: Re: AMD Bobcat cpufreq Message-ID: <20131018153650.GE1007@pd.tnic> References: <26801338.9419821382109781265.JavaMail.jza@saunalahti.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <26801338.9419821382109781265.JavaMail.jza@saunalahti.fi> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 18, 2013 at 06:23:01PM +0300, Joonas Saarinen wrote: > Borislav Petkov [bp@alien8.de] wrote: > >You can also try turbostat in tools/power/x86/turbostat/ > > > ># ./turbostat -i 1 > > We might be on to something. With work pinned on one core: > > cor CPU GHz TSC > 1.16 1.00 > 0 0 1.17 1.00 > 1 1 0.80 1.00 > > When both cores are occupied: > > cor CPU GHz TSC > 1.00 1.00 > 0 0 1.00 1.00 > 1 1 1.00 1.00 > > In this case both cores are limited to 1GHz, but it might be intentional > to avoid overheating. That's the boosting algorithm - the more parts of the silicon consume power, the more it gets spread out amongst them so that each one of them gets a smaller amount of the remaining power up to the TDP which is available for consumption. Also, AFAICT, on those machines the boosting algorithm involves the GPU so that it boosts too. This might be the reason why you don't see 1.33 GHz with one of the cores. > So there is some turbo functionality indeed. The frequency shown by > turbostat is still a bit off the target, not sure if there is any > actual problem though. Yeah, see above. I think all is fine with your box :) HTH. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --