1835950 - Spotlight message slow to render

Status: RESOLVED FIXED

(Firefox :: Messaging System, task, P1)

Description

[Punam Dahiya [:pdahiya]]

Scope of this task is to investigate users feedback on Firefox had grey background for 15-30 seconds before showing Spotlight window modal dialog.

Will be good to test spotlight on different platforms and low-end machines with slow network if the issue is replicable.

Comment 1

[Punam Dahiya [:pdahiya]]

NI @mcoman to help replicate the issue thanks!

Comment 2

[Ciprian Muresan [:cmuresan], Ecosystem QA]

Hey @punam, sorry for taking so much time with this request, we've had a full week.

Circling back here on Marius' behalf, I've managed to reproduce the slowness with the Spotlight window modal dialog. I've used this experiment in my attempts.

I've set-up a Windows 10 VM with multiple configurations to try and reproduce the issue. Here's a link to all the screen recordings that I made.

The good-machine_good-internet file is the baseline of how the spotlight appears, and the rest are different configurations of slower machine and internet. The "slow" machine was configured to have 1 core 3.6GHz, 2GB RAM, and 512 MB video memory, the "slowish" internet is 4mbps with 0% packet loss, and "slow" internet is 2mbps with 1% packet loss. The "good" machine was configured to have access to 8 cores 3.6GHz, 16GB RAM, and 8GB video memory.

While there is some noticeable slowness with the slow machine, the slow-machine_slow-internet file is the most slowness I've seen using any config.

Let me know if there's something more we can add here.

Comment 3

[Ed Lee :Mardak]

Attachment: really faded spotlight increased contrast.png

Thanks for the videos! I had to check multiple times to make sure it wasn't just some video compression artifact, but the slower videos actually do show a very faded spotlight content with transition (look for the blue primary button moving down). For the slowest video, when the spotlight becomes opaque, there is no transition and the image is already shown. This seems to suggest the rest of the spotlight content is waiting for the image to load to become opaque but the content is rendered much earlier allowing for the transition.

Comment 4

[Shane Hughes [:aminomancer]]

Attachment: Bug 1835950 - Make images in Spotlight modals load lazily. r=#omc-reviewers

Make the main Spotlight image always lazy load, and make other
Spotlight/about:welcome images lazy load if the configured src is an
http or https URL.

Comment 5

[Shane Hughes [:aminomancer]]

I figured out why it's so transparent when it's blocked by loading.
https://searchfox.org/mozilla-central/rev/1cfd3a3bc76a8d09cb4266576f30802753a80c83/toolkit/modules/SubDialog.sys.mjs#448-449

    // XXX: Hack to make focus during the dialog's load functions work. Make the element visible
    // sooner in DOMContentLoaded but mostly invisible instead of changing visibility just before
    // the dialog's load event.
    // Note that this needs to inherit so that hideDialog() works as expected.
    this._overlay.style.visibility = "inherit";
    this._overlay.style.opacity = "0.01";

This doesn't get unset until resizeDialog() which only happens _onLoad. Mystery solved!

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/336474fcd87b
Make images in Spotlight modals load lazily. r=omc-reviewers,dmose

Comment 7

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/336474fcd87b