Opened 2 years ago

Last modified 2 years ago

#26473 new defect

Tor Browser high CPU usage while browsing Facebook

Reported by: uzi Owned by: tbb-team
Priority: High Milestone:
Component: Applications/Tor Browser Version:
Severity: Major Keywords:
Cc: Actual Points:
Parent ID: Points:
Reviewer: Sponsor:

Description

Hi,
Tor Browser with a single page open - facebook, after scrolling a little CPU usage jumps to more than 60% of my fast notebook CPU.

See stack details in attachment.

Reproducibility: 100%

Tor Browser 7.5.5 (based on Mozilla Firefox 52.8.1) (32-bit)
Windows 10

Child Tickets

Attachments (1)

Sysinternals.png (96.8 KB) - added by uzi 2 years ago.

Download all attachments as: .zip

Change History (7)

Changed 2 years ago by uzi

Attachment: Sysinternals.png added

comment:1 Changed 2 years ago by cypherpunks

I'm also seeing high CPU usage on facebookCoreWWWi.onion (facebook's onion service), so much in fact that it started boiling my stomach from the cpu overheating... I have the latest HTTPS-E (with the fix), and on Linux...

comment:2 Changed 2 years ago by cypherpunks

Forgot to mention: not just on facebook, but on many other sites EVEN WITH THE SAFEST SECURITY SETTING which normally keeps the hungry JS in its cage.

comment:3 Changed 2 years ago by teor

The safest security setting turns off JavaScript, but it also turns off a lot of optimisations. (Because optimisations are fingerprintable.)

I'll leave it to the Tor Browser devs to analyse your stack trace.

comment:4 in reply to:  3 ; Changed 2 years ago by cypherpunks

Replying to teor:

The safest security setting turns off JavaScript, but it also turns off a lot of optimisations. (Because optimisations are fingerprintable.)

Optimisations of JS (i.e. basically JIT) have nothing to do with that since JS itself is entirely blocked, so why am I getting 100% CPU usage in a simple forum on high security setting? (precision: while it's loading up, when the page finally loads up it becomes better)

Last edited 2 years ago by cypherpunks (previous) (diff)

comment:5 Changed 2 years ago by cypherpunks

On the bright side: a FF60-esr based Tor Browser alpha is coming out very soon which will likely not have such a bug. On the darker side: using it will make you more fingerprintable.

comment:6 in reply to:  4 Changed 2 years ago by teor

Replying to cypherpunks:

Replying to teor:

The safest security setting turns off JavaScript, but it also turns off a lot of optimisations. (Because optimisations are fingerprintable.)

Optimisations of JS (i.e. basically JIT) have nothing to do with that since JS itself is entirely blocked, so why am I getting 100% CPU usage in a simple forum on high security setting? (precision: while it's loading up, when the page finally loads up it becomes better)

JavaScript isn't the only thing that browsers optimise.

Edit: Browsers optimise parts of the rendering pipelines as well.

Last edited 2 years ago by teor (previous) (diff)
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