From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752157AbaEBN3p (ORCPT ); Fri, 2 May 2014 09:29:45 -0400 Received: from mail-we0-f170.google.com ([74.125.82.170]:43939 "EHLO mail-we0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752048AbaEBN3o (ORCPT ); Fri, 2 May 2014 09:29:44 -0400 Message-ID: <53639DC9.2000701@linaro.org> Date: Fri, 02 May 2014 15:29:45 +0200 From: Daniel Lezcano User-Agent: Mozilla/5.0 (X11; Linux i686; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: "Rafael J. Wysocki" CC: peterz@infradead.org, mingo@elte.hu, amit.kucheria@linaro.org, linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Nicolas Pitre Subject: Re: [PATCH V2 1/2] sched: idle: Encapsulate the code to compile it out References: <1398859263-7632-1-git-send-email-daniel.lezcano@linaro.org> <2735426.75qSjG3M6Y@vostro.rjw.lan> <53635E5F.8070100@linaro.org> <5985714.f7hh9Ej59L@vostro.rjw.lan> In-Reply-To: <5985714.f7hh9Ej59L@vostro.rjw.lan> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/02/2014 02:09 PM, Rafael J. Wysocki wrote: > On Friday, May 02, 2014 10:59:11 AM Daniel Lezcano wrote: >> On 05/01/2014 12:56 AM, Rafael J. Wysocki wrote: >>> On Thursday, May 01, 2014 12:47:25 AM Rafael J. Wysocki wrote: >>>> On Wednesday, April 30, 2014 02:01:02 PM Daniel Lezcano wrote: >>>>> Encapsulate the large portion of cpuidle_idle_call inside another >>>>> function so when CONFIG_CPU_IDLE=n, the code will be compiled out. >>>>> Also that is benefitial for the clarity of the code as it removes >>>>> a nested indentation level. >>>>> >>>>> Signed-off-by: Daniel Lezcano >>>> >>>> Well, this conflicts with >>>> >>>> https://patchwork.kernel.org/patch/4071541/ >>>> >>>> which you haven't commented on and I still want cpuidle_select() to be able to >>>> return negative values because of >>>> >>>> https://patchwork.kernel.org/patch/4089631/ >>>> >>>> (and I have one more patch on top of these two that requires this). >>> >>> Moreover (along the lines of Nico said) after https://patchwork.kernel.org/patch/4071541/ >>> we actually don't need the #ifdef CONFIG_CPU_IDLE in your patch, because cpuidle_select() >>> for CONFIG_CPU_IDLE unset is a static inline returning a negative number and the compiler >>> should optimize out the blocks that depend on it being non-negative. >> >> Thanks for the head up. >> >> Actually that was to solve a compilation issue with the next patch when >> adding the cpuidle state in the struct rq. >> >> When the option CPU_IDLE is not set, the code assinging the cpu idle >> state in the rq is still there while in the struct rq the field is >> compiled out with the ifdef macro. If I rely on the compiler >> optimization, the compilation error will happen. > > I see. > > If you don't put the new idle_state field in struct_rq under the #ifdef, > you won't need to worry about the build problem. > > Alternatively, you can define > > #ifdef CONFIG_CPU_IDLE > static inline void rq_set_idle_state(struct rq *rq, struct cpuidle_state *state) > { > rq->idle_state = state; > } > #else > static inline void rq_set_idle_state(struct rq *rq, struct cpuidle_state *state) {} > #endif > > and use rq_set_idle_state() to set that field. Thanks, I will look at one or another solution. -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog