Commit d01079f3 authored by Mel Gorman's avatar Mel Gorman Committed by Linus Torvalds
Browse files

mm/mmap_lock: remove dead code for !CONFIG_TRACING configurations 

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.

[cuibixuan@huawei.com: fix warning when CONFIG_TRACING is not defined]
  Link: https://lkml.kernel.org/r/20210531033426.74031-1-cuibixuan@huawei.com

Link: https://lkml.kernel.org/r/20210520084809.8576-13-mgorman@techsingularity.net


Signed-off-by: default avatarMel Gorman <mgorman@techsingularity.net>
Signed-off-by: default avatarBixuan Cui <cuibixuan@huawei.com>
Reviewed-by: default avatarYang Shi <shy828301@gmail.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2bb6a033

mm/mmap_lock.c

+32 −27
Original line number Diff line number Diff line
@@ -153,6 +153,37 @@ static inline void put_memcg_path_buf(void) 
	rcu_read_unlock();

}



#define TRACE_MMAP_LOCK_EVENT(type, mm, ...)                                   \

	do {                                                                   \

		const char *memcg_path;                                        \

		preempt_disable();                                             \

		memcg_path = get_mm_memcg_path(mm);                            \

		trace_mmap_lock_##type(mm,                                     \

				       memcg_path != NULL ? memcg_path : "",   \

				       ##__VA_ARGS__);                         \

		if (likely(memcg_path != NULL))                                \

			put_memcg_path_buf();                                  \

		preempt_enable();                                              \

	} while (0)



#else /* !CONFIG_MEMCG */



int trace_mmap_lock_reg(void)

{

	return 0;

}



void trace_mmap_lock_unreg(void)

{

}



#define TRACE_MMAP_LOCK_EVENT(type, mm, ...)                                   \

	trace_mmap_lock_##type(mm, "", ##__VA_ARGS__)



#endif /* CONFIG_MEMCG */



#ifdef CONFIG_TRACING

#ifdef CONFIG_MEMCG

/*

 * Write the given mm_struct's memcg path to a percpu buffer, and return a

 * pointer to it. If the path cannot be determined, or no buffer was available
@@ -187,33 +218,6 @@ static const char *get_mm_memcg_path(struct mm_struct *mm) 
	return buf;

}



#define TRACE_MMAP_LOCK_EVENT(type, mm, ...)                                   \

	do {                                                                   \

		const char *memcg_path;                                        \

		local_lock(&memcg_paths.lock);				       \

		memcg_path = get_mm_memcg_path(mm);                            \

		trace_mmap_lock_##type(mm,                                     \

				       memcg_path != NULL ? memcg_path : "",   \

				       ##__VA_ARGS__);                         \

		if (likely(memcg_path != NULL))                                \

			put_memcg_path_buf();                                  \

		local_unlock(&memcg_paths.lock);			       \

	} while (0)



#else /* !CONFIG_MEMCG */



int trace_mmap_lock_reg(void)

{

	return 0;

}



void trace_mmap_lock_unreg(void)

{

}



#define TRACE_MMAP_LOCK_EVENT(type, mm, ...)                                   \

	trace_mmap_lock_##type(mm, "", ##__VA_ARGS__)



#endif /* CONFIG_MEMCG */



/*
@@ -239,3 +243,4 @@ 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 */