2020-03-08 15:55:08

by chenqiwu

Subject: [PATCH] sched/fair: fix build warning about undefined test_idle_cores()

From: chenqiwu <[email protected]>

The build with arm64's defconfig:
CONFIG_SCHED_MC=y
# CONFIG_SCHED_SMT is not set

Trigger the following warning due to test_idle_cores()'s definition
missing:
kernel/sched/fair.c:1524:20: warning: ‘test_idle_cores’ declared ‘static’
but never defined [-Wunused-function]

Move the CONFIG_SCHED_SMT ifdeffery around test_idle_cores()'s declaration
to fix it.

Signed-off-by: chenqiwu <[email protected]>
---
kernel/sched/fair.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 84594f8..d11d965 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1520,8 +1520,10 @@ static inline bool is_core_idle(int cpu)
return true;
}

+#ifdef CONFIG_SCHED_SMT
/* Forward declarations of select_idle_sibling helpers */
static inline bool test_idle_cores(int cpu, bool def);
+#endif

struct task_numa_env {
struct task_struct *p;
--
1.9.1

2020-03-08 18:35:33

by Mel Gorman

Subject: Re: [PATCH] sched/fair: fix build warning about undefined test_idle_cores()

On Sun, Mar 08, 2020 at 11:53:12PM +0800, [email protected] wrote:
> From: chenqiwu <[email protected]>
>
> The build with arm64's defconfig:
> CONFIG_SCHED_MC=y
> # CONFIG_SCHED_SMT is not set
>
> Trigger the following warning due to test_idle_cores()'s definition
> missing:
> kernel/sched/fair.c:1524:20: warning: ???test_idle_cores??? declared ???static???
> but never defined [-Wunused-function]
>
> Move the CONFIG_SCHED_SMT ifdeffery around test_idle_cores()'s declaration
> to fix it.
>
> Signed-off-by: chenqiwu <[email protected]>

Thanks. A fix has been merged to tip/sched/core as

commit 76c389ab2b5e300698eab87f9d4b7916f14117ba
Author: Valentin Schneider <[email protected]>
Date: Tue Mar 3 11:02:57 2020 +0000

sched/fair: Fix kernel build warning in test_idle_cores() for !SMT NUMA


--
Mel Gorman
SUSE Labs