1191412 - Getting incoherent "will-change memory consumption is too high" warnings

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Etienne Segonzac (:etienne)]

I think it happens on any app using will-change.
An easy way to reproduce is to install the test app from [1].

At launch we get the following warning in the console:
```
Will-change memory consumption is too high. Surface area covers 31680 px, budget is the document surface area multiplied by 3 (201600 px). Occurences of will-change over the budget will be ignored.
```

But the surface area (31680) is actually way smaller than the budget (201600) :)
At first I thought that maybe something was terribly wrong at the system app level, but removing all will-change uses from the system app yields the exact same message.


[1] https://github.com/gaia-components/fast-list/tree/master/examples/simple

Comment 1

[Etienne Segonzac (:etienne)]

Timing wise this could be related to bug 1103106.
Any idea?

Comment 2

[Benoit Girard (:BenWa)]

Looks like there's a logical error that slipped through that change:
http://mxr.mozilla.org/mozilla-central/source/layout/base/nsDisplayList.cpp#1233

Should warn on !onBudget instead.

Comment 3

[Benoit Girard (:BenWa)]

Here's the new warning. Note that I no longer mention the size of a particular surface since we look at the sum only:

Will-change memory consumption is too high. Budget limit is the document surface area multiplied by 3 (882015 px). Occurrences of will-change over the budget will be ignored.

Comment 4

[Benoit Girard (:BenWa)]

Attachment: MozReview Request: Bug 1191412 - Aurora-only: Fix will-change warning logic but not the string. r=roc

Bug 1191412 - Fix logic and text for the WillChange warning. r=roc

Comment 5

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Comment on attachment 8645146 [details]
MozReview Request: Bug 1191412 - Aurora-only: Fix will-change warning logic but not the string. r=roc

https://reviewboard.mozilla.org/r/15421/#review13819

Ship It!

Comment 6

[Benoit Girard (:BenWa)]

url:        https://hg.mozilla.org/integration/mozilla-inbound/rev/751d8abf0b7666484bbfd3397ae1e54e758d3fc9
changeset:  751d8abf0b7666484bbfd3397ae1e54e758d3fc9
user:       Benoit Girard <[e-mail]>
date:       Fri Aug 07 16:05:19 2015 -0400
description:
Bug 1191412 - Fix logic and text for the WillChange warning. r=roc

Comment 7

[Benoit Girard (:BenWa)]

Comment on attachment 8645146 [details]
MozReview Request: Bug 1191412 - Aurora-only: Fix will-change warning logic but not the string. r=roc

Approval Request Comment
[Feature/regressing bug #]: bug 1181976
[User impact if declined]: The error message will be printed at the wrong time confusing the user.
[Describe test coverage new/current, TreeHerder]: No changes in test
[Risks and why]: Very low, we're just changing the logic that's driving a warning message.
[String/UUID change made/needed]: This changes the willchange warning string. If we can't make a string change we should at least fix the warning logic. But the warning is a bit confusing without the string fix.

Comment 8

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/751d8abf0b76

Comment 9

[Sylvestre Ledru [:Sylvestre]]

Axel, Francesco, are you OK with this string change in 42? Thanks

Comment 10

[Francesco Lodolo [:flod]]

Given the audience, I would feel a lot of better if we just fix the logic, and keep the current string as it is in 42, especially considering this is a "spring" release. The string seems also the less problematic part of this issue.

Comment 11

[Benoit Girard (:BenWa)]

Comment on attachment 8645146 [details]
MozReview Request: Bug 1191412 - Aurora-only: Fix will-change warning logic but not the string. r=roc

Bug 1191412 - Aurora-only: Fix will-change warning logic but not the string. r=roc

Comment 12

[Benoit Girard (:BenWa)]

Here's a version of the patch that should be suitable to land on aurora.

[Tracking Requested - why for this release]: Patch is ready for uplift and isn't risky. Otherwise the warnings are all wrong. Asking for tracking so that we don't forget to land this for this release and ship the regression.

Comment 13

[Sylvestre Ledru [:Sylvestre]]

Comment on attachment 8645146 [details]
MozReview Request: Bug 1191412 - Aurora-only: Fix will-change warning logic but not the string. r=roc

thanks, let's take it!

Comment 14

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/releases/mozilla-aurora/rev/82eea4a52184