[golang-dev] Re: code review 6345044: cmd/gc: reduce memory consumption (issue 6345044)

http://codereview.appspot.com/6650054

https://codereview.appspot.com/6345044/

Thank you.

Hello dave@cheney.net, rsc@golang.org, bradfitz@golang.org,
lvd@google.com (cc: golang-dev@googlegroups.com),

Please take another look.


http://codereview.appspot.com/6345044/

I am still interested in this CL, but I would like to see a memory
profile showing what memory usage looks like before we start fixing
things. One way to get a memory profile would be to hook it up on
Linux to the C++ pprof (http://code.google.com/p/gperftools).

Hello dave@cheney.net, rsc@golang.org, bradfitz@golang.org,
lvd@google.com (cc: golang-dev@googlegroups.com),

Please take another look.


http://codereview.appspot.com/6345044/

I used Valgrind. When compiling godoc with 8g, the call counts are:

nod(): 357782 calls, 357782 calls to mal()
funcnode(): 21654 calls, 17648 mal()
unode(): 4470 calls, 3690 mal()

Sizes in bytes (8g):

sizeof(Node) = 180 (old size: 216)
sizeof(FuncNode) = 40
sizeof(UncommonNode) = 20

The theoretical difference in memory usage when compiling godoc is
approximately 340000*(216-180) = 12MiB. Actual difference as measured by
/usr/bin/time is 10MiB (=131-121).

---

Note: A new struct UncommonNode and function unode() has been added to
the changeset. Maybe we could move additional uncommon fields from Node
to UncommonNode before the decision to merge this changeset into Go is
made.

https://codereview.appspot.com/6345044/