[PATCH] percpu_counters: create lib/percpu_counter.c

- 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>

lib/Makefile

@@ -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

+/*
+ * 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

@@ -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
  */