make W=1 generates the following warning in mmap_lock.c for allnoconfig mm/mmap_lock.c:213:6: warning: no previous prototype for ‘__mmap_lock_do_trace_start_locking’ [-Wmissing-prototypes] void __mmap_lock_do_trace_start_locking(struct mm_struct *mm, bool write) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/mmap_lock.c:219:6: warning: no previous prototype for ‘__mmap_lock_do_trace_acquire_returned’ [-Wmissing-prototypes] void __mmap_lock_do_trace_acquire_returned(struct mm_struct *mm, bool write, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/mmap_lock.c:226:6: warning: no previous prototype for ‘__mmap_lock_do_trace_released’ [-Wmissing-prototypes] void __mmap_lock_do_trace_released(struct mm_struct *mm, bool write) On !CONFIG_TRACING configurations, the code is dead so put it behind an #ifdef. Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> --- mm/mmap_lock.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/mmap_lock.c b/mm/mmap_lock.c index dcdde4f722a4..03ee85c696ef 100644 --- a/mm/mmap_lock.c +++ b/mm/mmap_lock.c @@ -205,6 +205,7 @@ void trace_mmap_lock_unreg(void) #endif /* CONFIG_MEMCG */ +#ifdef CONFIG_TRACING /* * Trace calls must be in a separate file, as otherwise there's a circular * dependency between linux/mmap_lock.h and trace/events/mmap_lock.h. @@ -228,3 +229,4 @@ void __mmap_lock_do_trace_released(struct mm_struct *mm, bool write) TRACE_MMAP_LOCK_EVENT(released, mm, write); } EXPORT_SYMBOL(__mmap_lock_do_trace_released); +#endif /* CONFIG_TRACING */ -- 2.26.2