From f74ba0bb7d1a7230b1285a3b2c3c80cf4be8f595 Mon Sep 17 00:00:00 2001
From: Tim Chen <tim.c.chen@linux.intel.com>
Date: Mon, 9 Aug 2010 17:19:04 -0700
Subject: [PATCH] --- yaml --- r: 207229 b: refs/heads/master c:
 27f5e0f694fd0600274a76854636c0749e3bb1f6 h: refs/heads/master i:   207227:
 ea76ec19e7d6369b34b5f6adf10183399b78141d v: v3

---
 [refs]                               |  2 +-
 trunk/include/linux/percpu_counter.h | 11 +++++++++++
 trunk/lib/percpu_counter.c           | 27 +++++++++++++++++++++++++++
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index b39d9b5353c6..9c5f7a0fddbb 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4e60c86bd9e5a7110ed28874d0b6592186550ae8
+refs/heads/master: 27f5e0f694fd0600274a76854636c0749e3bb1f6
diff --git a/trunk/include/linux/percpu_counter.h b/trunk/include/linux/percpu_counter.h
index c88d67b59394..8a7d510ffa9c 100644
--- a/trunk/include/linux/percpu_counter.h
+++ b/trunk/include/linux/percpu_counter.h
@@ -40,6 +40,7 @@ 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(struct percpu_counter *fbc);
+int percpu_counter_compare(struct percpu_counter *fbc, s64 rhs);
 
 static inline void percpu_counter_add(struct percpu_counter *fbc, s64 amount)
 {
@@ -98,6 +99,16 @@ static inline void percpu_counter_set(struct percpu_counter *fbc, s64 amount)
 	fbc->count = amount;
 }
 
+static inline int percpu_counter_compare(struct percpu_counter *fbc, s64 rhs)
+{
+	if (fbc->count > rhs)
+		return 1;
+	else if (fbc->count < rhs)
+		return -1;
+	else
+		return 0;
+}
+
 static inline void
 percpu_counter_add(struct percpu_counter *fbc, s64 amount)
 {
diff --git a/trunk/lib/percpu_counter.c b/trunk/lib/percpu_counter.c
index aeaa6d734447..ec9048e74f44 100644
--- a/trunk/lib/percpu_counter.c
+++ b/trunk/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();