From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757357AbaFYO2B (ORCPT ); Wed, 25 Jun 2014 10:28:01 -0400 Received: from mail.active-venture.com ([67.228.131.205]:59961 "EHLO mail.active-venture.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756454AbaFYO2A (ORCPT ); Wed, 25 Jun 2014 10:28:00 -0400 X-Originating-IP: 108.223.40.66 Message-ID: <53AADC63.8080106@roeck-us.net> Date: Wed, 25 Jun 2014 07:27:47 -0700 From: Guenter Roeck User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: =?ISO-8859-1?Q?Uwe_Kleine-K=F6nig?= CC: Ingo Molnar , Russell King , Peter Zijlstra , Benjamin Herrenschmidt , linux-kernel@vger.kernel.org, Ingo Molnar , Paul Mackerras , Vincent Guittot , linuxppc-dev@lists.ozlabs.org, Dietmar Eggemann , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2] sched: Fix compiler warnings References: <1403658329-13196-1-git-send-email-linux@roeck-us.net> <20140625071416.GM14781@pengutronix.de> In-Reply-To: <20140625071416.GM14781@pengutronix.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/25/2014 12:14 AM, Uwe Kleine-König wrote: > On Tue, Jun 24, 2014 at 06:05:29PM -0700, Guenter Roeck wrote: >> Commit 143e1e28cb (sched: Rework sched_domain topology definition) >> introduced a number of functions with a return value of 'const int'. >> gcc doesn't know what to do with that and, if the kernel is compiled >> with W=1, complains with the following warnings whenever sched.h >> is included. >> >> include/linux/sched.h:875:25: warning: >> type qualifiers ignored on function return type >> include/linux/sched.h:882:25: warning: >> type qualifiers ignored on function return type >> include/linux/sched.h:889:25: warning: >> type qualifiers ignored on function return type >> include/linux/sched.h:1002:21: warning: >> type qualifiers ignored on function return type >> >> Commits fb2aa855 (sched, ARM: Create a dedicated scheduler topology table) >> and 607b45e9a (sched, powerpc: Create a dedicated topology table) introduce >> the same warning in the arm and powerpc code. >> >> Drop 'const' from the function declarations to fix the problem. >> >> The fix for all three patches has to be applied together to avoid >> compilation failures for the affected architectures. >> >> Cc: Dietmar Eggemann >> Cc: Peter Zijlstra >> Cc: Ingo Molnar >> Cc: Benjamin Herrenschmidt >> Cc: Vincent Guittot >> Signed-off-by: Guenter Roeck >> --- >> v2: Fix problem in all affected architectures with a single patch >> to avoid compilation errors. >> >> arch/arm/kernel/topology.c | 2 +- >> arch/powerpc/kernel/smp.c | 2 +- >> include/linux/sched.h | 8 ++++---- >> 3 files changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c >> index 9d85318..e35d880 100644 >> --- a/arch/arm/kernel/topology.c >> +++ b/arch/arm/kernel/topology.c >> @@ -275,7 +275,7 @@ void store_cpu_topology(unsigned int cpuid) >> cpu_topology[cpuid].socket_id, mpidr); >> } >> >> -static inline const int cpu_corepower_flags(void) >> +static inline int cpu_corepower_flags(void) >> { >> return SD_SHARE_PKG_RESOURCES | SD_SHARE_POWERDOMAIN; >> } > Maybe the author's intention was: > > static inline int cpu_corepower_flags(void) __attribute__((const)); > > ? > This specifies that the function has no side effects and the return value > only depends on the (here non-existing) function arguments. > Possibly, but either I am missing something or this doesn't compile. Guenter