1033456 - Consider removing about:blank from the list of URIs that we open in remote tabs

Status: RESOLVED WONTFIX

(Firefox :: Tabbed Browser, defect)

Description

[Mike Conley (:mconley) (:⚙️)]

tabbrowser.xml has functions to determine whether URLs that the user is browsing to should be opened in remote tabs or not.

about:blank is currently one of the pages that we do open in a remote tab.

That sure seems like a lot of machinery to fire up for a blank document. Are there good reasons for not just loading this in the parent process, and converting to a remote tab when the user browses away from about:blank?

Cc'ing jimm, who first noticed this, and felipe / billm, who I believe worked in this area in tabbrowser.xml.

Comment 1

[Dão Gottwald [:dao]]

(In reply to Mike Conley (:mconley) from comment #0)
> about:blank is currently one of the pages that we do open in a remote tab.

One of the many pages. Remote is the default. We special-case about: URIs and then we /remove/ about:blank from that list. If anything it seems that we should keep that list as short as possible.

> That sure seems like a lot of machinery to fire up for a blank document. Are
> there good reasons for not just loading this in the parent process, and
> converting to a remote tab when the user browses away from about:blank?

How would this be a net win?

Also note that content can open new about:blank tabs, which surely need to be remote. Being consistent, i.e. always letting them be remote, then seems better to me.

Comment 2

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

If there's some short-term win in making about:blank not be remote, that seems fine to me. But in general we want to be going in the opposite direction, so I don't think we should do this unless there's a good reason.

Comment 3

[Mike Conley (:mconley) (:⚙️)]

I guess the only real win I can see is that we don't have to set up the other process / IPC channel if the browser is set to open at about:blank, which could mean faster start-up time.

But that faster time is really just an illusion, now that I think about it - we'd still need to set up those things as soon as the user browses away.

jimm - were there other reasons to consider this that I haven't mentioned?

Comment 4

[Jim Mathies [:jimm]]

My concern was startup perf. A lot of people use ab as their homepage. Rather than guess, we can run some tests to see how this impacts startup, if it's negligible leave it remote. I'm a fan about pages being remote compat. too.