Opened 12 months ago

Last modified 12 months 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 12 months ago.

Download all attachments as: .zip

Change History (7)

Changed 12 months ago by uzi

Attachment: Sysinternals.png added

comment:1 Changed 12 months 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 12 months 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 12 months 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 12 months 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 12 months ago by cypherpunks (previous) (diff)

comment:5 Changed 12 months 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 12 months 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 12 months ago by teor (previous) (diff)
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