diff --git a/CHANGELOG.md b/CHANGELOG.md
index e8c264cc4..3e70cd98e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ will still be backwards compatible if only `url` is specified.
 - [#178](https://github.com/influxdb/telegraf/issues/178): redis plugin, multiple server thread hang bug
 - Fix net plugin on darwin
 - [#84](https://github.com/influxdb/telegraf/issues/84): Fix docker plugin on CentOS. Thanks @neezgee!
+- [#189](https://github.com/influxdb/telegraf/pull/189): Fix mem_used_perc. Thanks @mced!
 - [#192](https://github.com/influxdb/telegraf/issues/192): Increase compatibility of postgresql plugin. Now supports versions 8.1+
 
 ## v0.1.8 [2015-09-04]
diff --git a/plugins/rabbitmq/rabbitmq.go b/plugins/rabbitmq/rabbitmq.go
index 55b4b0a95..506e932ad 100644
--- a/plugins/rabbitmq/rabbitmq.go
+++ b/plugins/rabbitmq/rabbitmq.go
@@ -14,6 +14,7 @@ const DefaultURL = "http://localhost:15672"
 
 type Server struct {
 	URL      string
+	Name     string
 	Username string
 	Password string
 	Nodes    []string
@@ -70,6 +71,7 @@ type Node struct {
 var sampleConfig = `
 	# Specify servers via an array of tables
 	[[rabbitmq.servers]]
+	# name = "rmq-server-1" # optional tag
 	# url = "http://localhost:15672"
 	# username = "guest"
 	# password = "guest"
@@ -117,7 +119,10 @@ func (r *RabbitMQ) gatherServer(serv *Server, acc plugins.Accumulator) error {
 		return err
 	}
 
-	tags := map[string]string{}
+	tags := map[string]string{"url": serv.URL}
+	if serv.Name != "" {
+		tags["name"] = serv.Name
+	}
 
 	acc.Add("messages", overview.QueueTotals.Messages, tags)
 	acc.Add("messages_ready", overview.QueueTotals.MessagesReady, tags)
@@ -147,7 +152,7 @@ func (r *RabbitMQ) gatherServer(serv *Server, acc plugins.Accumulator) error {
 			continue
 		}
 
-		tags = map[string]string{"node": node.Name}
+		tags["node"] = node.Name
 
 		acc.Add("disk_free", node.DiskFree, tags)
 		acc.Add("disk_free_limit", node.DiskFreeLimit, tags)
diff --git a/plugins/system/ps/mem/mem_linux.go b/plugins/system/ps/mem/mem_linux.go
index 42a49a2b6..b2519ddd5 100644
--- a/plugins/system/ps/mem/mem_linux.go
+++ b/plugins/system/ps/mem/mem_linux.go
@@ -45,7 +45,7 @@ func VirtualMemory() (*VirtualMemoryStat, error) {
 	}
 	ret.Available = ret.Free + ret.Buffers + ret.Cached
 	ret.Used = ret.Total - ret.Free
-	ret.UsedPercent = float64(ret.Total-ret.Available) / float64(ret.Total) * 100.0
+	ret.UsedPercent = float64(ret.Used) / float64(ret.Total) * 100.0
 
 	return ret, nil
 }
diff --git a/plugins/system/ps/net/net_darwin.go b/plugins/system/ps/net/net_darwin.go
index 7fb21713c..0c518a736 100644
--- a/plugins/system/ps/net/net_darwin.go
+++ b/plugins/system/ps/net/net_darwin.go
@@ -7,7 +7,7 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/shirou/gopsutil/common"
+	"github.com/influxdb/telegraf/plugins/system/ps/common"
 )
 
 func NetIOCounters(pernic bool) ([]NetIOCountersStat, error) {
@@ -26,7 +26,7 @@ func NetIOCounters(pernic bool) ([]NetIOCountersStat, error) {
 			// skip first line
 			continue
 		}
-		if common.StringsHas(exists, values[0]) {
+		if common.StringContains(exists, values[0]) {
 			// skip if already get
 			continue
 		}