1256677 - (apz-checkerboard) [meta] Minimize checkerboarding

Status: NEW

(Core :: Panning and Zooming, defect, P3)

Description

[Kartikaya Gupta (email:[e-mail])]

We have a number of bugs filed for "regular" checkerboarding, which is something that is unavoidable with APZ. However, we can definitely work to reduce the amount of checkerboarding that users see, with the unattainable goal of zero checkerboarding. Or perhaps a more realistic goal based on telemetry data.

However, it's not useful to have a bunch of bugs opened for individual websites because often "fixing" checkerboarding for one website will make it worse for a lot of others. In general any attempt we make to reduce checkerboarding should be done in a general way and the results measured using the telemetry probes we have installed.

So what I propose is that we dupe all the "regular checkerboarding on X site" to this bug, and if we have specific ideas on how to reduce overall checkerboarding, we file those as individual bugs that block this one. The bugs duped to this one may provide useful information in terms of about:checkerboard logs.

Note that in some cases checkerboarding encountered on a particular site is exceptionally bad, usually due to some case that we're not handling properly (e.g. bug 1251638). I'm not counting those bugs as "regular" checkerboarding, and they can be handled separately.

Comment 13

[Kartikaya Gupta (email:[e-mail])]

According to telemetry [1] there was a small improvement in checkerboarding on Sep 9, for which the pushlog is [2]. From a quick glance bug 1295019 might have been the cause.

[1] https://mzl.la/2cLHidb
[2] https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=938ce16be25f9c551c19ef8938e8717ed3d41ff5&tochange=644b3de5d7a18b101d44a003bc27d50853dee4c9

Comment 16

[ovidiu boca[:Ovidiu]]

I talk with Kats on IRC about a bug with scroll bar, Here, https://streamable.com/8euce you can see a screen recorder with the issue. Kats please see the video and tell me your opinion, thanks.

Comment 17

[Kartikaya Gupta (email:[e-mail])]

(In reply to ovidiu boca[:Ovidiu] from comment #16)
> I talk with Kats on IRC about a bug with scroll bar, Here,
> https://streamable.com/8euce you can see a screen recorder with the issue.
> Kats please see the video and tell me your opinion, thanks.

That looks like bug 1251617. It's checkerboarding but during scrollbar drag.