Thanks Florian, considering it's roughly unmaintained right now, leaking, and showing up in perf profiles it sounds reasonable to remove the memory section. I've filed bug 1475301 [1] to allow us to measure USS off main thread; we can deal with adding that back in the future if it makes sense.
-e [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1475301 On Thu, Jul 12, 2018 at 12:41 AM, Florian Quèze <flor...@queze.net> wrote: > On Thu, Jul 12, 2018 at 1:18 AM, Eric Rahm <er...@mozilla.com> wrote: > > > What performance issues are you seeing? RSS and USS should be relatively > > lightweight and the polling frequency isn't very high. > > It seems ResidentUniqueDistinguishedAmount does blocking system calls, > resulting in blocking the main thread for several seconds in the worst > case. Here's a screenshot of a profile showing it: > https://i.imgur.com/DjRMQtY.png (unfortunately that profile is too big > and fails to upload with the 'share' feature). > > There's also a memory leak in the implementation, after leaving > about:performance open for a couple hours, there was more than 300MB > of JS "Function" and "Call" objects (about:memory screenshot: > https://i.imgur.com/21YNDru.png ) and the devtools' Memory tool shows > that this is coming from the code queuing updates to that subprocess > memory table: https://i.imgur.com/04M71hg.png > > Florian > > -- > Florian Quèze > _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform