1245590 - High CPU usage with screen share

Status: RESOLVED INCOMPLETE

(Core :: WebRTC, defect, P1)

Description

[Nils Ohlmeier [:drno]]

When investigating bug 1224845 I did some profiling of Firefox Hello calls on Linux with the following results:

A) plain A/V WebRTC call via appr.tc: ~80% CPU
B) Firefox Hello call with screen share: ~140% CPU
C) Firefox Hello call with screen share and without the patch from bug 1224845: ~220% CPU

Note: this is on an ASAN build with jprof on. So don't compare absolute numbers with your local numbers.

But the question is: can we reduce the overhead of screen share somehow?

Comment 1

[Nils Ohlmeier [:drno]]

Attachment: apprtc call profile

JProfile from a plain Audio & Video call between my Linux machine and my Mac. Note: this was done on an ASAN build.

Comment 2

[Nils Ohlmeier [:drno]]

Attachment: Firefox Hello call profile

JProfile from a Firefox Hello call with the automatic screen share. Again from the same Linux machine to the same Mac.
Note: again ASAN build

Comment 3

[msander]

Encoded resolution for screen sharing is large, up to 1920x1920. At the default 30 fps a significant hit to CPU isn't unexpected.

You could try setting the fps to 15 or setting a lower max resolution for the screen share. Lowering the resolution will impact the ability to read shared text on the screen however.

Comment 4

[Marco Castelluccio [:marco]]

In the profile I took, most of the time is spent in poll: https://cleopatra.io/#report=f71a7c620f0cbd72ff6fabc15352bb1743d99aff

(this is with a plain A/V call)

Comment 5

[Bulk Bug Changes for mreavy's org]

Mass change P2->P3 to align with new Mozilla triage process.

Comment 6

[Patricia Lawless]

Setting this to P1 for investigation and analysis so we can determine its true impact to the user.

Comment 7

[Michael Froman [:mjf]]

Marking this resolved/incomplete after no relevant updates in 4 years.