From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964987AbcALL6r (ORCPT ); Tue, 12 Jan 2016 06:58:47 -0500 Received: from casper.infradead.org ([85.118.1.10]:57211 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933822AbcALL6p (ORCPT ); Tue, 12 Jan 2016 06:58:45 -0500 Date: Tue, 12 Jan 2016 12:58:43 +0100 From: Peter Zijlstra To: Juri Lelli Cc: Viresh Kumar , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, rjw@rjwysocki.net, mturquette@baylibre.com, steve.muckle@linaro.org, vincent.guittot@linaro.org, morten.rasmussen@arm.com, dietmar.eggemann@arm.com Subject: Re: [RFC PATCH 04/19] cpufreq: bring data structures close to their locks Message-ID: <20160112115843.GD6357@twins.programming.kicks-ass.net> References: <1452533760-13787-1-git-send-email-juri.lelli@arm.com> <1452533760-13787-5-git-send-email-juri.lelli@arm.com> <20160111220708.GK6344@twins.programming.kicks-ass.net> <20160112092752.GV1084@ubuntu> <20160112112125.GA7015@e106622-lin> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160112112125.GA7015@e106622-lin> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 12, 2016 at 11:21:25AM +0000, Juri Lelli wrote: > I tried to see if something like for_each_domain() can be done, but here > we use list_for_each_entry() macro. Peter, do you mean something like > the following? > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index 78b1e2f..1a847a6 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -39,6 +39,7 @@ > static LIST_HEAD(cpufreq_governor_list); > static DEFINE_MUTEX(cpufreq_governor_mutex); > #define for_each_governor(__governor) \ > + lockdep_assert_held(&cpufreq_governor_mutex); \ > list_for_each_entry(__governor, &cpufreq_governor_list, governor_list) That fails for things like: if (blah) for_each_governor(...) { } which looks like valid C -- even though our Coding Style says the if should have { } on. I was thinking of either open coding the for statement and adding it to the first statement like: #define for_each_governor(__g) \ for (_g = list_first_entry(&cpufreq_governor_list, typeof(*_g), governor_list, lockdep_assert_held(), \ ..... ) Or use something like this: lkml.kernel.org/r/20150422154212.GE3007@worktop.Skamania.guest #define for_each_governor(_g) \ list_for_each_entry(_g, &cpufreq_governor_list, governor_list) if (lockdep_assert_held(..), false) ; else Which should preserve C syntax rules.