Thread M = Machine per OS Thread G = Goroutine (Coroutine) mcache mheap mspan mspan mspan mspan mspan mspan Stack = Write barrier on = Paused = Running = noscan mspan = GC Root = Alive = Unknown/Dead = Partial GC - Marking P1 M G2 Processor Core P = Logical Processor per Hardware Thread M = Machine per OS Thread G = Goroutine (Coroutine) mcache Stack All Grey objects are scanned and all white object can be collected = Write barrier on = Paused = Running = GC Root = Alive = Unknown/Dead = Partial