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[PATCH] percpu_counters: create lib/percpu_counter.c

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

Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Ravikiran G Thirumalai 2006-06-23 02:05:40 -07:00 committed by Linus Torvalds
parent d09042da72
commit 3cbc564024
3 changed files with 47 additions and 42 deletions
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1
lib/Makefile
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@ -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

46
lib/percpu_counter.c Normal file
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@ -0,0 +1,46 @@
/*
* 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);

42
mm/swap.c
View File

@ -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
*/