1544317 - some new tabs >1.5mb while the others are ~262kb

Status: NEW

(Firefox :: New Tab Page, defect, P2)

Description

[Dietrich Ayala (:dietrich)]

Attachment: Screen Shot 2019-04-14 at 12.50.11 PM.png

68.0a1 (2019-04-11) (64-bit) Mac OS X

Screenshot attached of about:performance

Seems weird that some empty tabs are 4x more memory than the rest.

Comment 1

[Alex Thayer [:alexical] (she/her)]

Could you include an about:memory report?

Comment 2

[Dietrich Ayala (:dietrich)]

Attachment: memory-report.json.gz

In this one, similar pattern but different numbers. Most are around ~260kb and two are ~871kb.

Comment 3

[Eric Rahm [:erahm]]

There's something like 13 about:blank windows reported under the parent process, all with 0.07MB. Most of that is under js-realm/classes. TBH I'm not sure where about:performance is getting it's numbers, this might just be a reporting problem.

My standard recommendation here is to start in safe mode and see if you get the same behavior, I'm reasonably sure this is extension related.

Comment 4

[Dietrich Ayala (:dietrich)]

Confirmed that in safe mode, the heavier about:blank windows are gone, so it must be that extensions are able to make this happen.

Seems like that shouldn't be possible with WebExtension APIs?

Comment 5

[Alex Thayer [:alexical] (she/her)]

Going to kick this to WebExtensions now not knowing the answer to comment 4.

Comment 6

[Kris Maglione [:kmag]]

I don't see any evidence that this has anything to do with the extension framework, and I don't really have much to go on.

What is in the new tabs? Activity stream? about:blank? Something provided by an extension?

In the latter two cases, it's possible that an extension could be responsible, but that would not, strictly speaking, be a bug. Certainly not a framework bug. In the Activity Stream case, that would be an AS bug.

What about:memory entries do these about:performance entries correspond to? What are their real URLs? Without knowing that, there isn't really anything I can say about them.

Comment 7

[Alex Thayer [:alexical] (she/her)]

(In reply to Kris Maglione [:kmag] from comment #6)

I don't see any evidence that this has anything to do with the extension framework, and I don't really have much to go on.

What is in the new tabs? Activity stream? about:blank? Something provided by an extension?

In the latter two cases, it's possible that an extension could be responsible, but that would not, strictly speaking, be a bug. Certainly not a framework bug. In the Activity Stream case, that would be an AS bug.

What about:memory entries do these about:performance entries correspond to? What are their real URLs? Without knowing that, there isn't really anything I can say about them.

Fair enough. Dietrich, assuming you can still reproduce this, can you get the exact URLs for the entries in about:performance?

Also, if you could try narrowing this down to a particular extension, that could be very helpful.

Comment 8

[Mike Conley (:mconley) (:⚙️)]

In about:performance, double-clicking on those tabs should switch you to them. Are you able to find a difference between the tabs that have lower memory consumption over the ones with higher memory consumption? If they're all Activity Stream, for example, are the images displayed different?

Comment 9

[Dietrich Ayala (:dietrich)]

Great help, thanks mconley! I had no idea you could do that.

They are new-tab pages.

I thought I was able to reproduce without any extensions enabled, but now I cannot reproduce even with all my extensions enabled. It must be because I'm looking.

I'll keep trying to narrow down to a specific extension.

Some other maybe relevant info:

• I usually have 7-10 windows open which have a new empty tab as the active tab

• The heavy tabs are always two of those new tabs

• My home page setting is "Blank Page"

• Always only 2 new-tabs using way more memory, and the rest about the same (~260kb)

• Those 2 new-tabs are always ~same memory usage as each other

• Their size fluctuates - I've seen from ~800kb to 23mb (!) per tab for these two

• No pattern in how much memory used by them - but always went up or down, didn't stay the same between restarts

Comment 10

[Dietrich Ayala (:dietrich)]

Right now I have a bunch of empty new-tabs but two that are 2.2mb each according to about:performance. They're both in windows that I haven't been interacting with.

Screenshot: https://i.imgur.com/pZJAYm6.png

Comment 11

[Scott [:thecount] Downe]

I tried to take a look at this from an activity stream/pocket point of view.

I tried to reproduce the original issue but couldn't.

I did noticed a few things that seem like maybe concerning.

My numbers in about:performance are much more consistent, and I tried turning on and off various new tab features to see if any of them causes more issues than others, still relatively similar.

The one thing I did notice, my numbers were much higher. With everything turned off in new tab, I still had about 3.6mb in memory. As I turned on features, it settles at around 6mb. Seems high compared to the original issue's report of 260 kb.

Comment 12

[Wayne Mery (:wsmwk)]

Dietrich, do you still experience this issue?

Comment 13

[Dietrich Ayala (:dietrich)]

I don't know if I'll have time to test anytime soon. Based on comment #11, is maybe much larger memory use for others than even I'm seeing 🤷🏽 Up to you if worth investigating or not.