[PATCH] sched/fair: Conditionally enable test_idle_cores() forward declaration

[PATCH] sched/fair: Conditionally enable test_idle_cores() forward declaration

[Anshuman Khandual]

test_idle_cores()'s definition and all it's call sites are enclosed within
CONFIG_SCHED_SMT. Hence the forward declaration needs to be conditionally
enabled in order to prevent build warnings like the following.

kernel/sched/fair.c:1524:20: warning: ‘test_idle_cores’ declared ‘static’
but never defined [-Wunused-function]
 static inline bool test_idle_cores(int cpu, bool def);
                    ^~~~~~~~~~~~~~~

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: sfr@canb.auug.org.au
Cc: linux-next@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
This patch solves a build problem that exists on next-20200302.

 kernel/sched/fair.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 84594f8..827087f 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1521,7 +1521,9 @@ static inline bool is_core_idle(int cpu)
 }
 
 /* Forward declarations of select_idle_sibling helpers */
+#ifdef CONFIG_SCHED_SMT
 static inline bool test_idle_cores(int cpu, bool def);
+#endif
 
 struct task_numa_env {
 	struct task_struct *p;
-- 
2.7.4

Re: [PATCH] sched/fair: Conditionally enable test_idle_cores() forward declaration

[Vincent Guittot]

Hi Anshuman,

On Tue, 3 Mar 2020 at 05:30, Anshuman Khandual
<anshuman.khandual@arm.com> wrote:
>
> test_idle_cores()'s definition and all it's call sites are enclosed within
> CONFIG_SCHED_SMT. Hence the forward declaration needs to be conditionally
> enabled in order to prevent build warnings like the following.
>
> kernel/sched/fair.c:1524:20: warning: ‘test_idle_cores’ declared ‘static’
> but never defined [-Wunused-function]
>  static inline bool test_idle_cores(int cpu, bool def);
>                     ^~~~~~~~~~~~~~~

similar patches has already been sent:
https://lore.kernel.org/lkml/20200226121244.7524-1-valentin.schneider@arm.com/
https://lore.kernel.org/patchwork/patch/1201059/

>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Juri Lelli <juri.lelli@redhat.com>
> Cc: Vincent Guittot <vincent.guittot@linaro.org>
> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Ben Segall <bsegall@google.com>
> Cc: Mel Gorman <mgorman@suse.de>
> Cc: sfr@canb.auug.org.au
> Cc: linux-next@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> This patch solves a build problem that exists on next-20200302.
>
>  kernel/sched/fair.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 84594f8..827087f 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -1521,7 +1521,9 @@ static inline bool is_core_idle(int cpu)
>  }
>
>  /* Forward declarations of select_idle_sibling helpers */
> +#ifdef CONFIG_SCHED_SMT
>  static inline bool test_idle_cores(int cpu, bool def);
> +#endif
>
>  struct task_numa_env {
>         struct task_struct *p;
> --
> 2.7.4
>