No need for pauseCheckMemory. Also remove unused flags.

Dockerfile

@@ -21,11 +21,11 @@ ENV LD_LIBRARY_PATH "/usr/local/lib"
 # Install DGraph and update dependencies to right versions.
 RUN go get -v github.com/robfig/glock && \
 	go get -v github.com/dgraph-io/dgraph/... && \
-	glock sync github.com/dgraph-io/dgraph
+	glock sync github.com/dgraph-io/dgraph && echo "v0.1"
 
 # Run some tests, don't build an image if we're failing tests.
 RUN go test github.com/dgraph-io/dgraph/...
 
-# Create the data directory. This directory should be mapped
+# Create the dgraph and data directory. These directories should be mapped
 # to host machine for persistence.
-RUN mkdir /data
+RUN mkdir /dgraph && mkdir /data

posting/lists.go

@@ -31,9 +31,6 @@ import (
 	"github.com/zond/gotomic"
 )
 
-var minmemory = flag.Uint64("min_ram_mb", 2048,
-	"If RAM usage exceeds this, start periodically evicting posting lists"+
-		" from memory.")
 var maxmemory = flag.Uint64("max_ram_mb", 4096,
 	"If RAM usage exceeds this, we stop the world, and flush our buffers.")
 
@@ -46,32 +43,35 @@ type counters struct {
 
 func (c *counters) periodicLog() {
 	for _ = range c.ticker.C {
-		added := atomic.LoadUint64(&c.added)
-		merged := atomic.LoadUint64(&c.merged)
-		var pending uint64
-		if added > merged {
-			pending = added - merged
-		}
+		c.log()
+	}
+}
 
-		glog.WithFields(logrus.Fields{
-			"added":     added,
-			"merged":    merged,
-			"clean":     atomic.LoadUint64(&c.clean),
-			"pending":   pending,
-			"mapsize":   lhmap.Size(),
-			"dirtysize": dirtymap.Size(),
-		}).Info("List Merge counters")
+func (c *counters) log() {
+	added := atomic.LoadUint64(&c.added)
+	merged := atomic.LoadUint64(&c.merged)
+	var pending uint64
+	if added > merged {
+		pending = added - merged
 	}
+
+	glog.WithFields(logrus.Fields{
+		"added":     added,
+		"merged":    merged,
+		"clean":     atomic.LoadUint64(&c.clean),
+		"pending":   pending,
+		"mapsize":   lhmap.Size(),
+		"dirtysize": dirtymap.Size(),
+	}).Info("List Merge counters")
 }
 
 func NewCounters() *counters {
 	c := new(counters)
 	c.ticker = time.NewTicker(time.Second)
-	go c.periodicLog()
 	return c
 }
 
-var MIB, MAX_MEMORY, MIN_MEMORY uint64
+var MIB, MAX_MEMORY uint64
 
 func aggressivelyEvict(ms runtime.MemStats) {
 	// Okay, we exceed the max memory threshold.
@@ -105,7 +105,7 @@ func gentlyMerge(ms runtime.MemStats) {
 	var hs []gotomic.Hashable
 	dirtymap.Each(func(k gotomic.Hashable, v gotomic.Thing) bool {
 		hs = append(hs, k)
-		return len(hs) > 400
+		return len(hs) >= 400
 	})
 
 	idx := 0
@@ -133,18 +133,14 @@ func gentlyMerge(ms runtime.MemStats) {
 		}
 		mergeAndUpdate(l, ctr)
 	}
+	ctr.log()
 }
 
 func checkMemoryUsage() {
 	MIB = 1 << 20
 	MAX_MEMORY = *maxmemory * MIB
-	MIN_MEMORY = *minmemory * MIB // Not being used right now.
 
 	for _ = range time.Tick(5 * time.Second) {
-		if atomic.LoadInt32(&pauseCheckMemory) == 1 {
-			continue
-		}
-
 		var ms runtime.MemStats
 		runtime.ReadMemStats(&ms)
 		if ms.Alloc > MAX_MEMORY {
@@ -156,7 +152,6 @@ func checkMemoryUsage() {
 	}
 }
 
-var pauseCheckMemory int32
 var stopTheWorld sync.RWMutex
 var lhmap *gotomic.Hash
 var dirtymap *gotomic.Hash
@@ -242,10 +237,13 @@ func queueAll(ch chan gotomic.Hashable, c *counters) {
 }
 
 func MergeLists(numRoutines int) {
-	atomic.StoreInt32(&pauseCheckMemory, 1)
+	// We're merging all the lists, so just create a new dirtymap.
+	dirtymap = gotomic.NewHash()
 
 	ch := make(chan gotomic.Hashable, 10000)
 	c := NewCounters()
+	go c.periodicLog()
+	defer c.ticker.Stop()
 	go queueAll(ch, c)
 
 	wg := new(sync.WaitGroup)
@@ -255,5 +253,4 @@ func MergeLists(numRoutines int) {
 	}
 	wg.Wait()
 	c.ticker.Stop()
-	atomic.StoreInt32(&pauseCheckMemory, 0)
 }