digraph uploading {

	node [shape=box];

	subgraph user_space {
		rank=same;
		"disk cache" -> "send buffer" [label="copy into peer's send buffer (copy)"]
		"send buffer" -> "encrypted send buffer" [label="encrypt in-place (no copy)" style=dashed];
	}

	subgraph kernel {
		rank=same;
		"kernel page cache";
		"socket kernel buffer"
	}

	"encrypted send buffer" -> "socket kernel buffer" [label="write() to socket (copy)"];
	"kernel page cache" -> "disk cache" [label="read() from file (copy)"]
}

