X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=lib%2Fpercpu_counter.c;h=ec9048e74f448ce3a79522aef9ac5f4c4b350737;hb=dcded10f6dce10411b16134ce9cc87bfdf75c13f;hp=aeaa6d7344475518a3b73b3a7062106e77cadcea;hpb=33dbe6114047496a5b6fee0941c52dad41250043;p=~andy%2Flinux

diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c
index aeaa6d73444..ec9048e74f4 100644
--- a/lib/percpu_counter.c
+++ b/lib/percpu_counter.c
@@ -137,6 +137,33 @@ static int __cpuinit percpu_counter_hotcpu_callback(struct notifier_block *nb,
 	return NOTIFY_OK;
 }
 
+/*
+ * Compare counter against given value.
+ * Return 1 if greater, 0 if equal and -1 if less
+ */
+int percpu_counter_compare(struct percpu_counter *fbc, s64 rhs)
+{
+	s64	count;
+
+	count = percpu_counter_read(fbc);
+	/* Check to see if rough count will be sufficient for comparison */
+	if (abs(count - rhs) > (percpu_counter_batch*num_online_cpus())) {
+		if (count > rhs)
+			return 1;
+		else
+			return -1;
+	}
+	/* Need to use precise count */
+	count = percpu_counter_sum(fbc);
+	if (count > rhs)
+		return 1;
+	else if (count < rhs)
+		return -1;
+	else
+		return 0;
+}
+EXPORT_SYMBOL(percpu_counter_compare);
+
 static int __init percpu_counter_startup(void)
 {
 	compute_batch_value();