base/allocator/partition_allocator/dot/layers.dot

digraph G {
  graph[bgcolor=transparent]
  node[shape=box,style="filled,rounded",color=deepskyblue]

  subgraph cluster_tc {
    label = "Thread Cache"
    rankdir = LR
    {rank=same;TLS1,TLS2,TLSn}
    TLS1->TLS2[style=invisible,dir=none]
    TLS2->TLSn[style=dotted,dir=none]
  }

  subgraph cluster_central {
    label = "Central Allocator (per-partition lock)"
    fast[label="slot span freelists (fast path)"]
    slow[label="slot span management (slow path)"]
    # Forces slow path node beneath fast path node.
    fast->slow[style=invisible,dir=none]
  }

  # Forces thread-external subgraph beneath thread cache subgraph.
  TLS2->fast[style=invisible,dir=none]
}