From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from elcamino.pasemi.com (elcamino.pasemi.com [67.155.108.98]) by ozlabs.org (Postfix) with ESMTP id 61113DDE0E for ; Thu, 19 Jun 2008 12:59:01 +1000 (EST) Message-Id: From: Olof Johansson To: Nathan Lynch In-Reply-To: <1213835374-10868-4-git-send-email-ntl@pobox.com> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Mime-Version: 1.0 (Apple Message framework v924) Subject: Re: [RFC/PATCH 3/3] adjust cpu power for secondary threads on POWER6 Date: Wed, 18 Jun 2008 21:58:59 -0500 References: <1213835374-10868-1-git-send-email-ntl@pobox.com> <1213835374-10868-4-git-send-email-ntl@pobox.com> Cc: linuxppc-dev@ozlabs.org, Ingo Molnar , Paul Mackerras , linux-kernel@vger.kernel.org, Anton Blanchard List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi, > +static unsigned int pseries_cpu_power(int cpu, unsigned int > default_power) > +{ > + struct device_node *np; > + unsigned int thread, power; > + > + if (!cpu_has_feature(CPU_FTR_ASYM_POWER)) > + return default_power; > + > + power = default_power; Why not just NULL out the cpu_power function pointers on platforms that don't have the feature bit instead? (or the other way around: NULL by default, and set only on platforms that have imbalanced threads. It'd be even nicer to do so without using up a cpu feature bit, since it'd then only be used in determining whether to set the ppc_md function pointer or not, but I don't know if there's a convenient way to probe for this at runtime (cpu device tree node properties?). -Olof