1401012 - rasterize takes a long time while first loading activity stream

Status: NEW

(Core :: Graphics, defect, P2)

Description

[Florian Quèze [:florian]]

Here is a startup profile https://perfht.ml/2x9I7at on the quantum reference hardware. The content process #2 is loading activity stream for about:home, and there's 541ms spent in 'rasterize', that seems long.

This was a cold startup profile, so it's possible there's some main thread IO for some system libraries.

Comment 1

[Milan Sreckovic [:milan] (needinfo for best results)]

Is this a regression from older 57 or older releases?

Comment 2

[Naveed Ihsanullah [:naveed]]

@Bas: Is this still a priority with WebRender coming? If yes we can mark it perf:p1

Comment 3

[Daniel Holbert [:dholbert]]

Brief observation during triage meeting:
- 58% of this long-rasterize time is in "NtWaitForAlertByThreadId" (95 of 164 samples)
- 73% *of those NtWaitForAlertByThreadId samples* are from calls from the D3D11 CContext::TID3D11DeviceContext_SetShader_ API.

Link: https://perfht.ml/2lEulZ5

Comment 4

[Bas Schouten (:bas.schouten)]

(In reply to Naveed Ihsanullah [:naveed] from comment #2)
> @Bas: Is this still a priority with WebRender coming? If yes we can mark it
> perf:p1

Don't expect webrender to be on nightly until well into 2018, nor is it unclear which performance issues will be fixed by it. Although we can be pretty sure the sites hitting performance issues will be different, at least.. So take that into account when triaging.

I'll look into this though.

Comment 5

[Randell Jesup [:jesup] (needinfo me)]

Florian - can you re-profile with (and without) WebRender on reference (or other low-end) hardware?  We'll re-triage once we have that.  Thanks!

Comment 6

[Florian Quèze [:florian]]

https://perfht.ml/2GJNzar - 198ms. And that was when painting about:home in a second window, so not even the first load.

https://perfht.ml/2GK0PvJ This one is a cold startup. The first refresh driver tick in the privileged content process takes 3435ms A bit later there's a 849ms rasterize marker.

https://perfht.ml/2Gvuo3V Cold startup with webrender enabled.