1857081 - A lot of time spent in memory allocation/deallocation on the leaves benchmark

Status: NEW

(Core :: Graphics: WebRender, task, P3)

Description

[Nicolas Silva [:nical]]

Profile: https://share.firefox.dev/46snaEW

The profile was coolected by Bas: using https://browserbench.org/MotionMark1.2/developer.html

• select motionmark/leaves
• "Keep at fixed complexity"
  • set the boz that appears next to motionmark/leaves at 2500
• run

The largest bottleneck appears to be the content thread however we spend a fair amount of time on scene building and frame building with timings in the realm of 10-12ms and a large portion of both are in memory allocation/deallocation (mostly growing vectors).

Chrome is doing better than us at this test, but looks like something webrender should be able to handle pretty well.

Comment 1

[Nicolas Silva [:nical]]

Jeff noted that the memory measurements in the profile can inflate the cost of allocation and deallocations, so while it's probably still bad, it may be bad to a lesser extent than what the profile suggests. We'd need to profile using etw, perf or xcode to know for sure.