scollector: include slab as free mem for linux os.mem

cmd/scollector/collectors/collectors.go

@@ -79,10 +79,10 @@ const (
 	osDiskPctFreeDesc    = "The percent_free property indicates what percentage of the disk is available."
 	osDiskTotalDesc      = "The space_total property indicates in bytes how much total space is on the disk."
 	osDiskUsedDesc       = "The space_used property indicates in bytes how much space is used on the disk."
-	osMemFreeDesc        = "Number, in bytes, of physical memory currently unused and available."
-	osMemPctFreeDesc     = "The percent of free memory. In Linux free memory includes memory used by buffers and cache."
-	osMemTotalDesc       = "Total amount, in bytes, of physical memory available to the operating system."
-	osMemUsedDesc        = "The amount of used memory. In Linux this excludes memory used by buffers and cache."
+	osMemFreeDesc        = "The number of bytes of physical memory currently unused and available. In Linux this metric considers buffers, cache, and slab to be free memory."
+	osMemPctFreeDesc     = "The percent of free memory. In Linux this metric considers buffers, cache, and slab to be free memory."
+	osMemTotalDesc       = "The total amount of physical memory available in bytes to the operating system."
+	osMemUsedDesc        = "The amount of used memory. In Linux this metric excludes buffers, cache, from used memory."
 	osNetAdminStatusDesc = "The desired state of the interface. The testing(3) state indicates that no operational packets can be passed. When a managed system initializes, all interfaces start with ifAdminStatus in the down(2) state. As a result of either explicit management action or per configuration information retained by the managed system, ifAdminStatus is then changed to either the up(1) or testing(3) states (or remains in the down(2) state)."
 	osNetBroadcastDesc   = "The rate at which broadcast packets are sent or received on the network interface."
 	osNetBytesDesc       = "The rate at which bytes are sent or received over the network interface."

cmd/scollector/collectors/procstats_linux.go

@@ -54,13 +54,13 @@ func c_procstats_linux() (opentsdb.MultiDataPoint, error) {
 	}); err != nil {
 		Error = err
 	}
-	mem := make(map[string]float64)
+	mem := make(map[string]int64)
 	if err := readLine("/proc/meminfo", func(s string) error {
 		m := meminfoRE.FindStringSubmatch(s)
 		if m == nil {
 			return nil
 		}
-		i, err := strconv.ParseFloat(m[2], 64)
+		i, err := strconv.ParseInt(m[2], 10, 64)
 		if err != nil {
 			return err
 		}
@@ -70,11 +70,12 @@ func c_procstats_linux() (opentsdb.MultiDataPoint, error) {
 	}); err != nil {
 		Error = err
 	}
-	Add(&md, osMemTotal, int(mem["MemTotal"])*1024, nil, metadata.Gauge, metadata.Bytes, osMemTotalDesc)
-	Add(&md, osMemFree, (int(mem["MemFree"])+int(mem["Buffers"])+int(mem["Cached"]))*1024, nil, metadata.Gauge, metadata.Bytes, osMemFreeDesc)
-	Add(&md, osMemUsed, (int(mem["MemTotal"])-(int(mem["MemFree"])+int(mem["Buffers"])+int(mem["Cached"])))*1024, nil, metadata.Gauge, metadata.Bytes, osMemUsedDesc)
+	bufferCacheSlab := mem["Buffers"] + mem["Cached"] + mem["Slab"]
+	Add(&md, osMemTotal, mem["MemTotal"]*1024, nil, metadata.Gauge, metadata.Bytes, osMemTotalDesc)
+	Add(&md, osMemFree, (mem["MemFree"]+bufferCacheSlab)*1024, nil, metadata.Gauge, metadata.Bytes, osMemFreeDesc)
+	Add(&md, osMemUsed, (mem["MemTotal"]-mem["MemFree"]+bufferCacheSlab)*1024, nil, metadata.Gauge, metadata.Bytes, osMemUsedDesc)
 	if mem["MemTotal"] != 0 {
-		Add(&md, osMemPctFree, (mem["MemFree"]+mem["Buffers"]+mem["Cached"])/mem["MemTotal"]*100, nil, metadata.Gauge, metadata.Pct, osMemFreeDesc)
+		Add(&md, osMemPctFree, (float64(mem["MemFree"])+float64(bufferCacheSlab))/float64(mem["MemTotal"])*100, nil, metadata.Gauge, metadata.Pct, osMemFreeDesc)
 	}
 
 	num_cores := 0