Element::AddSizeOfExcludingThis never actually measures the ElementData. Neither does the Servo_Element_SizeOfExcludingThisAndCVs function it calls: that measures some of the things the ElementData stores, but not the ElementData itself. We should add this measurement. It can be somewhat significant (e.g. > 5MB on the HTML single-page spec).

We already measure (in Rust code) the things hanging off it, but overlooked the object itself. This patch adds measurement on the C++ side.

bz: one line review! :)

Comment on attachment 8905771 [details] [diff] [review] Measure ElementData Review of attachment 8905771 [details] [diff] [review]: ----------------------------------------------------------------- r+. Feel free to delay landing the servo patch until you have some other reason to land something there, since it's just a comment.

https://hg.mozilla.org/integration/mozilla-inbound/rev/8f53032e5451db68972e8aaeb6a394c4c271073a Bug 1397472 - Measure ElementData. r=bholley.

Pushed by nnethercote@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/8f53032e5451 Measure ElementData. r=bholley.

At bz's suggestion, I ended up putting this in a new bucket "layout/servo-element-data-objects" instead of lumping it in under DOM nodes. For the single-page HTML5 spec I got 3.4 MiB in that bucket.