1124767 - FlameGraph._drawTicks can be very very slow when completely zoomed in

Status: RESOLVED FIXED

(DevTools :: Performance Tools (Profiler/Timeline), defect)

Description

[Victor Porof [:vporof][:vp]]

Attachment: profile.json

For long recordings, drawing ticks is super slow.

Attached is a profile made with the new perf tool showing that we spend 50% of our time just in that function.

Comment 1

[Victor Porof [:vporof][:vp]]

Attachment: v1

Turns out that when we were super zoomed in, we were drawing lines form -a bazillion pixels to +a bazillion pixels. Needless to say, that's close to almost 2xbazillion more lines that we need.

Comment 2

[Jordan Santell [:jsantell] [@jsantell]]

Comment on attachment 8553242 [details] [diff] [review]
v1

Review of attachment 8553242 [details] [diff] [review]:
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hopefully this improves performance to get the sweet spot of less than big O bazillian

Comment 3

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/aaa2586234e3