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Commit 3cbc5640 authored by Ravikiran G Thirumalai's avatar Ravikiran G Thirumalai Committed by Linus Torvalds
Browse files

[PATCH] percpu_counters: create lib/percpu_counter.c 



- Move percpu_counter routines from mm/swap.c to lib/percpu_counter.c

Signed-off-by: default avatarRavikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent d09042da

lib/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ obj-$(CONFIG_TEXTSEARCH) += textsearch.o 
obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o

obj-$(CONFIG_TEXTSEARCH_BM) += ts_bm.o

obj-$(CONFIG_TEXTSEARCH_FSM) += ts_fsm.o

obj-$(CONFIG_SMP) += percpu_counter.o



obj-$(CONFIG_SWIOTLB) += swiotlb.o

lib/percpu_counter.c

0 → 100644
+46 −0
Original line number Diff line number Diff line 
/*

 * Fast batching percpu counters.

 */



#include <linux/percpu_counter.h>

#include <linux/module.h>



void percpu_counter_mod(struct percpu_counter *fbc, long amount)

{

	long count;

	long *pcount;

	int cpu = get_cpu();



	pcount = per_cpu_ptr(fbc->counters, cpu);

	count = *pcount + amount;

	if (count >= FBC_BATCH || count <= -FBC_BATCH) {

		spin_lock(&fbc->lock);

		fbc->count += count;

		*pcount = 0;

		spin_unlock(&fbc->lock);

	} else {

		*pcount = count;

	}

	put_cpu();

}

EXPORT_SYMBOL(percpu_counter_mod);



/*

 * Add up all the per-cpu counts, return the result.  This is a more accurate

 * but much slower version of percpu_counter_read_positive()

 */

long percpu_counter_sum(struct percpu_counter *fbc)

{

	long ret;

	int cpu;



	spin_lock(&fbc->lock);

	ret = fbc->count;

	for_each_possible_cpu(cpu) {

		long *pcount = per_cpu_ptr(fbc->counters, cpu);

		ret += *pcount;

	}

	spin_unlock(&fbc->lock);

	return ret < 0 ? 0 : ret;

}

EXPORT_SYMBOL(percpu_counter_sum);

mm/swap.c

+0 −42
Original line number Diff line number Diff line
@@ -480,48 +480,6 @@ static int cpu_swap_callback(struct notifier_block *nfb, 
#endif /* CONFIG_HOTPLUG_CPU */

#endif /* CONFIG_SMP */



#ifdef CONFIG_SMP

void percpu_counter_mod(struct percpu_counter *fbc, long amount)

{

	long count;

	long *pcount;

	int cpu = get_cpu();



	pcount = per_cpu_ptr(fbc->counters, cpu);

	count = *pcount + amount;

	if (count >= FBC_BATCH || count <= -FBC_BATCH) {

		spin_lock(&fbc->lock);

		fbc->count += count;

		*pcount = 0;

		spin_unlock(&fbc->lock);

	} else {

		*pcount = count;

	}

	put_cpu();

}

EXPORT_SYMBOL(percpu_counter_mod);



/*

 * Add up all the per-cpu counts, return the result.  This is a more accurate

 * but much slower version of percpu_counter_read_positive()

 */

long percpu_counter_sum(struct percpu_counter *fbc)

{

	long ret;

	int cpu;



	spin_lock(&fbc->lock);

	ret = fbc->count;

	for_each_possible_cpu(cpu) {

		long *pcount = per_cpu_ptr(fbc->counters, cpu);

		ret += *pcount;

	}

	spin_unlock(&fbc->lock);

	return ret < 0 ? 0 : ret;

}

EXPORT_SYMBOL(percpu_counter_sum);

#endif



/*

 * Perform any setup for the swap system

 */