Open Bug 1618968 Opened 4 years ago Updated 1 year ago

First frame rendering takes longer in Fenix than Fennec due to WebRender


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





(Reporter: sefeng, Unassigned)


(Blocks 1 open bug)



There profiles were taken on Pixel 3.

Based on these 2 profiles, there was a 470ms gap between the request is finished to the first paint, and it was only 30ms in Fennec. Looks like the delay was due the first composite took 420ms in Fenix.

Blocks: wr-android
Component: Graphics → Graphics: WebRender
Flags: needinfo?(ktaeleman)

Hi Sean, would it be possible to include the renderer thread in the Fenix profile?

Flags: needinfo?(sefeng)

Hi Jamie,

Try, would you be able to see it this time?

The renderer thread was included, but you need to click that " 6/7 tracks visible" button to make it visible.

Flags: needinfo?(sefeng)

Oh sorry! Silly me, I always forget about that!

Looks like all the time is spent compiling shaders, which is sort of expected on first launch. Is this taking place on a fresh profile? Does a subsequent app launch exhibit the same behaviour, or is it faster?

It was a fresh install and the first launch.

Seems like subsequent app launch doesn't exhibit the same behaviour, much faster. This is the profile from a subsequent app launch Around 100ms this time.

Priority: -- → P3
Flags: needinfo?(ktaeleman)
Blocks: wr-android-perf
No longer blocks: wr-android
Severity: normal → S3
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