add unreclaim metric, this closes #719

mem/mem.go

@@ -58,6 +58,7 @@ type VirtualMemoryStat struct {
 	Shared         uint64 `json:"shared"`
 	Slab           uint64 `json:"slab"`
 	SReclaimable   uint64 `json:"sreclaimable"`
+	SUnreclaim     uint64 `json:"sunreclaim"`
 	PageTables     uint64 `json:"pagetables"`
 	SwapCached     uint64 `json:"swapcached"`
 	CommitLimit    uint64 `json:"commitlimit"`

mem/mem_linux.go

@@ -83,6 +83,8 @@ func VirtualMemoryWithContext(ctx context.Context) (*VirtualMemoryStat, error) {
 		case "SReclaimable":
 			sReclaimable = true
 			ret.SReclaimable = t * 1024
+		case "SUnreclaim":
+			ret.SUnreclaim = t * 1024
 		case "PageTables":
 			ret.PageTables = t * 1024
 		case "SwapCached":

mem/mem_test.go

@@ -77,7 +77,7 @@ func TestVirtualMemoryStat_String(t *testing.T) {
 		UsedPercent: 30.1,
 		Free:        40,
 	}
-	e := `{"total":10,"available":20,"used":30,"usedPercent":30.1,"free":40,"active":0,"inactive":0,"wired":0,"laundry":0,"buffers":0,"cached":0,"writeback":0,"dirty":0,"writebacktmp":0,"shared":0,"slab":0,"sreclaimable":0,"pagetables":0,"swapcached":0,"commitlimit":0,"committedas":0,"hightotal":0,"highfree":0,"lowtotal":0,"lowfree":0,"swaptotal":0,"swapfree":0,"mapped":0,"vmalloctotal":0,"vmallocused":0,"vmallocchunk":0,"hugepagestotal":0,"hugepagesfree":0,"hugepagesize":0}`
+	e := `{"total":10,"available":20,"used":30,"usedPercent":30.1,"free":40,"active":0,"inactive":0,"wired":0,"laundry":0,"buffers":0,"cached":0,"writeback":0,"dirty":0,"writebacktmp":0,"shared":0,"slab":0,"sreclaimable":0,"sunreclaim":0,"pagetables":0,"swapcached":0,"commitlimit":0,"committedas":0,"hightotal":0,"highfree":0,"lowtotal":0,"lowfree":0,"swaptotal":0,"swapfree":0,"mapped":0,"vmalloctotal":0,"vmallocused":0,"vmallocchunk":0,"hugepagestotal":0,"hugepagesfree":0,"hugepagesize":0}`
 	if e != fmt.Sprintf("%v", v) {
 		t.Errorf("VirtualMemoryStat string is invalid: %v", v)
 	}