Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752545Ab0ATV6I (ORCPT ); Wed, 20 Jan 2010 16:58:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752379Ab0ATV6G (ORCPT ); Wed, 20 Jan 2010 16:58:06 -0500 Received: from ozlabs.org ([203.10.76.45]:58612 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752296Ab0ATV6C (ORCPT ); Wed, 20 Jan 2010 16:58:02 -0500 From: Michael Neuling To: Peter Zijlstra cc: Joel Schopp , ego@in.ibm.com, Andreas Herrmann , linux-kernel@vger.kernel.org, Ingo Molnar , linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 2/2] powerpc: implement arch_scale_smt_power for Power7 In-reply-to: <1264020517.4283.1117.camel@laptop> References: <1264017638.5717.121.camel@jschopp-laptop> <1264017847.5717.132.camel@jschopp-laptop> <1264020517.4283.1117.camel@laptop> Comments: In-reply-to Peter Zijlstra message dated "Wed, 20 Jan 2010 21:48:37 +0100." X-Mailer: MH-E 8.2; nmh 1.3; GNU Emacs 23.1.1 Date: Thu, 21 Jan 2010 10:58:01 +1300 Message-ID: <29111.1264024681@neuling.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 582 Lines: 15 > > On Power7 processors running in SMT4 mode with 2, 3, or 4 idle threads > > there is performance benefit to idling the higher numbered threads in > > the core. > > So this is an actual performance improvement, not only power savings? It's primarily a performance improvement. Any power/energy savings would be a bonus. Mikey -- 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/