From: Arnd Bergmann <arnd@xxxxxxxx> These four functions have a normal definition for CONFIG_FAIR_GROUP_SCHED, and empty one that is only referenced when FAIR_GROUP_SCHED is disabled but CGROUP_SCHED is still enabled. If both are turned off, the functions are still defined but the misisng prototype causes a W=1 warning: kernel/sched/fair.c:12544:6: error: no previous prototype for 'free_fair_sched_group' kernel/sched/fair.c:12546:5: error: no previous prototype for 'alloc_fair_sched_group' kernel/sched/fair.c:12553:6: error: no previous prototype for 'online_fair_sched_group' kernel/sched/fair.c:12555:6: error: no previous prototype for 'unregister_fair_sched_group' Move the alternatives into the header as static inline functions with the correct combination of #ifdef checks to avoid the warning without adding even more complexity. [A different patch with the same description got applied by accident and was later reverted, but the original patch is still missing] Fixes: 7aa55f2a5902 ("sched/fair: Move unused stub functions to header") Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- A patch with the same commit log has --- kernel/sched/fair.c | 13 ------------- kernel/sched/sched.h | 11 +++++++++++ 2 files changed, 11 insertions(+), 13 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 2048138ce54b..82b82fa1d81b 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -12927,19 +12927,6 @@ int sched_group_set_idle(struct task_group *tg, long idle) return 0; } -#else /* CONFIG_FAIR_GROUP_SCHED */ - -void free_fair_sched_group(struct task_group *tg) { } - -int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) -{ - return 1; -} - -void online_fair_sched_group(struct task_group *tg) { } - -void unregister_fair_sched_group(struct task_group *tg) { } - #endif /* CONFIG_FAIR_GROUP_SCHED */ diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 2e5a95486a42..8f5df5250b8d 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -436,10 +436,21 @@ static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) extern int tg_nop(struct task_group *tg, void *data); +#ifdef CONFIG_FAIR_GROUP_SCHED extern void free_fair_sched_group(struct task_group *tg); extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent); extern void online_fair_sched_group(struct task_group *tg); extern void unregister_fair_sched_group(struct task_group *tg); +#else +static inline void free_fair_sched_group(struct task_group *tg) { } +static inline int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) +{ + return 1; +} +static inline void online_fair_sched_group(struct task_group *tg) { } +static inline void unregister_fair_sched_group(struct task_group *tg) { } +#endif + extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, struct sched_entity *se, int cpu, struct sched_entity *parent); -- 2.39.2