Commit bf1d89c8 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Linus Torvalds
Browse files

lib: percpu_count_sum() 



Provide an accurate version of percpu_counter_read.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 52d9f3b4

include/linux/percpu_counter.h

+17 −1
Original line number Diff line number Diff line
@@ -34,13 +34,24 @@ void percpu_counter_init(struct percpu_counter *fbc, s64 amount); 
void percpu_counter_destroy(struct percpu_counter *fbc);

void percpu_counter_set(struct percpu_counter *fbc, s64 amount);

void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch);

s64 percpu_counter_sum_positive(struct percpu_counter *fbc);

s64 __percpu_counter_sum(struct percpu_counter *fbc);



static inline void percpu_counter_add(struct percpu_counter *fbc, s64 amount)

{

	__percpu_counter_add(fbc, amount, FBC_BATCH);

}



static inline s64 percpu_counter_sum_positive(struct percpu_counter *fbc)

{

	s64 ret = __percpu_counter_sum(fbc);

	return ret < 0 ? 0 : ret;

}



static inline s64 percpu_counter_sum(struct percpu_counter *fbc)

{

	return __percpu_counter_sum(fbc);

}



static inline s64 percpu_counter_read(struct percpu_counter *fbc)

{

	return fbc->count;
@@ -107,6 +118,11 @@ static inline s64 percpu_counter_sum_positive(struct percpu_counter *fbc) 
	return percpu_counter_read_positive(fbc);

}



static inline s64 percpu_counter_sum(struct percpu_counter *fbc)

{

	return percpu_counter_read(fbc);

}



#endif	/* CONFIG_SMP */



static inline void percpu_counter_inc(struct percpu_counter *fbc)

lib/percpu_counter.c

+3 −3
Original line number Diff line number Diff line
@@ -52,7 +52,7 @@ EXPORT_SYMBOL(__percpu_counter_add); 
 * Add up all the per-cpu counts, return the result.  This is a more accurate

 * but much slower version of percpu_counter_read_positive()

 */

s64 percpu_counter_sum_positive(struct percpu_counter *fbc)

s64 __percpu_counter_sum(struct percpu_counter *fbc)

{

	s64 ret;

	int cpu;
@@ -64,9 +64,9 @@ s64 percpu_counter_sum_positive(struct percpu_counter *fbc) 
		ret += *pcount;

	}

	spin_unlock(&fbc->lock);

	return ret < 0 ? 0 : ret;

	return ret;

}

EXPORT_SYMBOL(percpu_counter_sum_positive);

EXPORT_SYMBOL(__percpu_counter_sum);



void percpu_counter_init(struct percpu_counter *fbc, s64 amount)

{