In addition to forwarding Monitor updates, the Monitor actor should also be able to start/stop one or more reporting agents. One type of reporting agent we're interested in is Unique Set Size for all processes.

Comment on attachment 8456914 [details] [diff] [review] Add USS reporting to the Monitor actor. Paul, care to take a look?

(you need to remove the dbg-client changes)

Carry over Paul's r+ (if git-bz feels generous).

Comment on attachment 8457944 [details] [diff] [review] Add USS reporting to the Monitor actor. So git-bz didn't feel generous, carrying over by hand. Indeed the dbg-client.jsm changes are already landed as bug 1039448, and the shell.js change wasn't necessary. Removed and rebased.

Sorry for the hassle, but is there a Try run for this?

Rebased, try run: https://tbpl.mozilla.org/?tree=Try&rev=11db123bbf42

Comment on attachment 8459478 [details] [diff] [review] Add USS reporting to the Monitor actor. (this whole carrying over thing feels prehistoric)

This apparently broke an xpcshell test: https://tbpl.mozilla.org/php/getParsedLog.php?id=44318344&tree=Fx-Team Backed out in https://hg.mozilla.org/integration/fx-team/rev/76c587b06771

Fixed test.

Comment on attachment 8462571 [details] [diff] [review] Add USS reporting to the Monitor actor. Carry over Paul's r+.

test_monitor_actor.js | Test timed out

Jan - did you try to call update as a start callback?

Yes I tried that, still times out on try https://tbpl.mozilla.org/?tree=Try&rev=0e3578240e90 (even though it works on my machine). Doesn't look intermittent.

`residentUnique` is not available on Windows and Mac. Only call `MonitorActor.prototype._addAgent(USSAgent)` if `residentUnique` is available (or on Linux). And enable the test just for Linux,

Fixed for non-linux platforms by auto-removing update agents whose `start()` method throws. Try: https://tbpl.mozilla.org/?tree=Try&rev=380f64d73706

Comment on attachment 8463346 [details] [diff] [review] Add USS reporting to the Monitor actor. Paul, asking you to re-review because I slightly changed the way update agents work (see previous comment). Do you think this approach makes sense? If you do, and if the change really fixes non-linux xpcshell tests, please land the patch for me.