Another YouTube glitch: 100% of CPU core usage

[Vort]

@Pathduck said in Another YouTube glitch: 100% of CPU core usage:

Have you tried to exclude the Vivaldi folder from scanning for testing purposes?

Looks like restarting of Kaspersky fixed the problem O_o
Thanks. Will make more tests, but looks like problem is fixed.

[Pathduck]

@Vort said in Another YouTube glitch: 100% of CPU core usage:

Looks like restarting of Kaspersky fixed the problem O_o

Great find - it's always either extensions or 3rd-party software
Please report the issue to Kaspersky support.

Removing ru/ and changing it to en/ do not help.

Good point. I guess this should be reported to Vivaldi, and tell them to update their pages. Also redirect should not be forced if user manually adds /en/ to the url.
https://vivaldi.com/bugreport/

Direct link to 3.2 Stable:
https://downloads.vivaldi.com/stable/Vivaldi.3.2.1967.47.x64.exe
(If you still need to test if this issue is only with 3.3)

Also, maybe it's still somehow related to service workers, and since you're running uBO, try to add this rule in "My Filters" it should block the YT sw process.
||youtube.com/sw.js
I just block most service workers I can find anyway

[Vort]

@Pathduck said in Another YouTube glitch: 100% of CPU core usage:

Good point. I guess this should be reported to Vivaldi, and tell them to update their pages. Also redirect should not be forced if user manually adds /en/ to the url.

I have made VIV-1003.
Not a perfect description of a problem, but I have tried.

By the way, do Vivaldi installers are downloaded with specific language embedded in them?
If not, then I do not see the reason for making separate lists of binaries for each language.

Great find - it's always either extensions or 3rd-party software

Please report the issue to Kaspersky support.

Maybe the cause is high energy particle, which flipped some bit in my RAM
So I will do this if problem rises again.
For now glitch state is lost.

[Vort]

@Pathduck said in Another YouTube glitch: 100% of CPU core usage:

(If you still need to test if this issue is only with 3.3)

Yeah, problem appeared again.
During yesterday evening, all was fine.
Then, at night, this happened:

And at morning I realized that the same bug appeared again.

I have made test with Vivaldi 3.2.1967.47 - bug reproduces with this version too.

[Vort]

I have tried to add d:\Vivaldi\ folder to Kaspersky exceptions -> no difference.

"L" patch for Kaspersky 20.0.14.1085 was released at 03.08.2020, which corresponds to 10.08.2020 date for file c:\Program Files (x86)\Kaspersky Lab\Kaspersky Free 20.0\SecurityProductInformation.ini.
So it was not possible for fresh update to make bad things.

Since problem also reproduces with Vivaldi 3.2.1967.47, I think that the reason is some sort of data corruption somewhere (hope that not because of failed hardware).
Another attempt can be a computer restart, which may reset theoretical corruption in OS memory. But for now I will not do this.

[Vort]

@Pathduck PC restart and several restarts of Kaspersky did not fixed the problem this time.
So problem inside broswer is the main hypothesis now.

upd. Default RAM checker showed no errors.

[Vort]

Bug also reproduces inside virtual machine without Kaspersky installed.

[Vort]

@Gwen-Dragon said in Another YouTube glitch: 100% of CPU core usage:

Which VM? Which Guest OS? Which Host OS?

VM: VirtualBox 6.1.12.
Host: Windows 7 SP1 x64
Guest: Windows 7 SP1 x64

But the problem reproducing only with my profile (which I have copied from the host).
I'm trying to understand now how to discover which parts of my profile are glitchy.
Most likely, glitch is contained inside Service Worker folder, but I am not sure: folders have links between them.

[Pathduck]

I really have no clue at this point. Do you have a Win10 VM to test with?

Since you already have uBlock installed, and the theory is that a specific service-worker is causing it (YT), try blocking it in My Filters like this:
||youtube.com/sw.js

Are any other SW showing up?
Does it help in the VM to delete the Service Worker folder or IndexedDB folders?

[Vort]

@Pathduck said in Another YouTube glitch: 100% of CPU core usage:

I really have no clue at this point.

Either changing of glitchy profile to become clean profile + glitch or changing clean profile to become glitchy.
Not sure that I will be able to do this, but I will try.

Since you already have uBlock installed, and the theory is that a specific service-worker is causing it (YT), try blocking it in My Filters like this:

Getting rid of bug is only the part of the problem.
I want to catch it

[Pathduck]

@Vort said in Another YouTube glitch: 100% of CPU core usage:

I want to catch it

I understand that, but first you need to be able to isolate exactly what's causing it, otherwise it's only making guesses.

[Vort]

@Pathduck said in Another YouTube glitch: 100% of CPU core usage:

I understand that, but first you need to be able to isolate exactly what's causing it, otherwise it's only making guesses.

Of course.
That is what I mean by catching.
I don't want to catch air

---

Looks like, reproduction success or fail is related to amount of data inside Vivaldi\User Data\Default\Service Worker\CacheStorage\.
There was 74 folders there with total size of 400 MB.
Now in VM only 5 of them are left: related to rbc.ua, nytimes.com, meduza.io, regex101.com and developers.google.com. Of course, developers.google.com, since I am reproducing bug with its help. Total size now is 140 MB (so I have removed small ones, and big ones are left).
So if I am removing 3767d53b4dac3b74ffab051bbbfcbdca6b593df5 (rbc.ua), access to developers.google.com do not produces hang.
Looks like I was filling those caches for a long time and hit some overflow in browser several days ago.
But I may be wrong, of course.

[Vort]

Crazy things.
Bug reproduction depends on amount of free space on disk c:\.
When there are ~1.3 GB of free space, then it reproduces.
When there are ~0.3 GB of free space, then it not reproduces.

upd. ^^ that happened inside VM.
Then I tried to copy large file to disk d:\, when Vivaldi is located -> bug was still reproducing. Deleted that file.
Next I have copied large file to disk c:\, bug stopped reproducing.
Then I deleted large file from disk c:\ and bug is still not reproducing.
(with every test browser was restarted)
This not looks like a fix!!

[Vort]

I was right that glitch is related to Service Workers.
It is reproducing in VM with clean profile + problematic Service Worker folder + QuotaManager file.
I have made several additional tests:

1. Windows 8.1 VM with 1 GiB of RAM: no reproduction.
2. Another real PC with Windows 7 and 4 GiB of RAM: no reproduction.
3. Same PC as before + same Win 7 VM as before, but with RAM amount expanded from 1 GiB to 2 GiB: no reproduction.

So the requirements for problem to happen looks like this:

• Problematic (large?) Service Worker folder + QuotaManager file.
• 1.3 GiB+ free space on disk c:\.
• 1 GiB of RAM (inside VM).
• Windows 7.

It is approximate conditions, it is hard to say more without having browser source code or at least debug information.
Since it is reproducing on my main PC with 8 GiB of RAM, 1 GiB of RAM is not a fixed requirement, most likely it depends on amount of contents inside Service Worker folder and 140 MB of data inside corresponds to 1 GiB of RAM.

Can anyone test Vivaldi_Glitchy_ServiceWorker_UserData.7z (uploaded to dropmefiles) profile with Vivaldi 3.3.2022.39 (this is not strict requirement) inside Windows 7 VM with 1 GiB of RAM?
@Pathduck , @Gwen-Dragon ?

[Vort]

@Gwen-Dragon said in Another YouTube glitch: 100% of CPU core usage:

But it would be interesting, if Chromium 85.0.4183.102 has the same issue!

Yes, it have.
I have copied Service Worker and QuotaManager to c:\Users\Vort\AppData\Local\Google\Chrome\User Data\Default\ and I see the same hang when I visit https://developers.google.com/speed/public-dns/docs/using?partial=1&hl=en with Chrome 85.0.4183.102.

If yes, it is a Chr bug and should be reported to Chromium devs at https://bugs.chromium.org/p/chromium/issues/list. They should check and fix.

But it is also Vivaldi bug!
All discussion is here on the forum.
And I doubt that I can explain the problem to them.
(I'm not the user of Chrome!)
Also it may be that bug is created by Vivaldi (but reproducing in both browsers).
So it is better if someone else will create bugreport (either at Vivaldi, Chrome or both).

[Pathduck]

@Vort Problem is, you still have to reproduce the issue in a clean profile, whether it's Chromium or Vivaldi.

Otherwise the likely answer will be "you have some corrupted cache or misbehaving service worker, clear your cache, problem solved"

Honestly, I doubt anyone apart from us curious testers here at the Vivaldi forum will be interested in recreating an obscure bug caused by some files in a user's cache on an old, rarely used OS. Just the way it is. You've done a great job of investigation though, kudos to you for that

[Vort]

@Pathduck said in Another YouTube glitch: 100% of CPU core usage:

Otherwise the likely answer will be "you have some corrupted cache or misbehaving service worker, clear your cache, problem solved"

That is one of the reasons why I don't want to have a deals with Google.

@Vort Problem is, you still have to reproduce the issue in a clean profile, whether it's Chromium or Vivaldi.

"Use browser for several years?"
I know that it is possible to obtain such steps, but it makes sense for me to discover them only if I can be almost entirely sure that my work will not be thrown away.

Honestly, I doubt anyone apart from us curious testers here at the Vivaldi forum will be interested in recreating an obscure bug caused by some files in a user's cache on an old, rarely used OS. Just the way it is. You've done a great job of investigation though, kudos to you for that

Thanks.
So I am just clearing my cache.
I will not delete archives with glitch for some time for the case if someone want to continue this investigation.
(Try to contact me in various ways in this case).

The thing is that this bug may be very important.
Later versions of Windows may just have slightly different reproduction conditions.
But developers usually do not care.
They have different goals, making great software is a side-effect of their activity.

[TbGbe]

@Gwen-Dragon said in Another YouTube glitch: 100% of CPU core usage:

Vivaldi can only fix it after they got a fix from Chromium core upstream.

Yes, but surely Vivaldi are also contributors to Chromium development??

Vivaldi devs could investigate further to determine EXACT problem, then report to Chromium or even produce their own patch/fix and submit to Chromium!

[Vort]

By the way, exactly the same bug happens if many files are accumulated in User Data\Default\IndexedDB folder.
I was forced to clear it as well, since clearing of Service Worker did not helped anymore.