1671859 - Not responding notification from Firefox (in titlebar) when switching to a background window

Status: NEW

(Core :: Graphics, defect, P3)

Description

[Asif Youssuff]

I have occasionally been seeing "Not Responding" appended to Firefox windows when using Firefox on Windows, and grabbed a ETW profile as this occurred. I am hoping there is something interesting here, but if not, I can try to run the Firefox profiler instead to try to capture more data.

Basic information

Steps to Reproduce:

1. Start Firefox session with three windows open
2. Use Firefox for a little while
3. Use Alt-tab to switch to a background window

Expected Results:

Firefox window appears.

Actual Results:

Firefox showed the other window pretty much immediately, but the window titlebar appeared and showed "Not Responding" appended to the window title.

In the profile, the freeze occurred ~2-3 seconds before I captured the profile.

---

More information

Profile URL: https://drive.google.com/file/d/1HeBJ71gXPuRcanMkf3rxL4TBt7qwrwe7/view?usp=sharing

This is a ETW profile, per: https://randomascii.wordpress.com/2015/09/01/xperf-basics-recording-a-trace-the-ultimate-easy-way/

Basic systems configuration:

OS version: Windows 10

GPU model: Intel HD 600

Number of cores: 2

Amount of memory (RAM): 8GB

Thanks so much for your help.

Comment 1

[Asif Youssuff]

Here is a Firefox profile when switching to another tab: https://share.firefox.dev/3k9ok0o - same symptom of showing "Not Responding" in the titlebar momentarily.

Note, I don't have the title bar enabled in Firefox.

Comment 2

[Asif Youssuff]

Attachment: image.png

This is what the window looks like when this happens.

Comment 3

[Asif Youssuff]

Attachment: about:support

Comment 4

[Markus Stange [:mstange]]

Windows puts this text on top of our window if the parent process main thread takes too long to respond to a native UI event.

(In reply to Asif Youssuff from comment #1)

Here is a Firefox profile when switching to another tab: https://share.firefox.dev/3k9ok0o

In this profile, the parent process is momentarily frozen because it is blocked in a synchronous IPC message to the GPU process. The GPU process main thread isn't responding because it's spending a long time in DeviceManagerDx::CreateDecoderDevice and D3D11DXVA2Manager::CreateDecoder.

There's a heavy lack of samples during that time. So maybe it's CPU starvation again?
Most of the sampled stacks are waiting in NtGdiDdDDIMakeResident or NtGdiDdDDIMapGpuVirtualAddress.

Comment 5

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:jimm, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 6

[Arthur K. (he/him)]

(In reply to Asif Youssuff from comment #1)

Here is a Firefox profile when switching to another tab: https://share.firefox.dev/3k9ok0o - same symptom of showing "Not Responding" in the titlebar momentarily.

Note, I don't have the title bar enabled in Firefox.

Is this still an issue using 85?

Comment 7

[Asif Youssuff]

Still an issue in Firefox 87 - see new profile: https://share.firefox.dev/2YqnvXR

Comment 8

[Arthur K. (he/him)]

I'm looking at the profile and I see kernel32.dll, kernelbase.dll and nt.dll referenced there. those are Windows DLLs. Can you check your drive health with something like Crystal Disk Info? When you files the bug you were still on Windows 2004. Have you updated to 20H2 yet?

Comment 9

[Asif Youssuff]

Crystal Disk Info says the disk is good; it is a fairly new WDS250G2B0A-00SM50 drive.

Windows version seems to be 19042.746.

Comment 10

[Asif Youssuff]

Continuing to see this in the latest Nightly - new profile: https://share.firefox.dev/38HuVuL