Inactive memory mapped video windows playback loosing a lot of frames

[igoryonya]

When I attach windows locally and they are memory mapped, windows' priority is real time only when they are active. For example, when I run firefox on youtube or a video player, if the window is active, the video plays fine, but when it's inactive, the video plays like a slide show.
Remotely attached xpra windows (displayed with codecs, such as h264), don't have such problem. Inactive windows don't slow down, as they when they are memory mapped. Remotely attached codec windows play normal, even if they are inactive. Also, local windows ran without xpra behave normally, i.e. don't slow down, if inactive.

xpra v2.5-r22135
Ubuntu 18.04.2 LTS
Linux ws02800008006 4.4.0-64-generic #85-Ubuntu SMP Mon Feb 20 11:50:30 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Oland XT [Radeon HD 8670 / R7 250/350]
06:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV710 [Radeon HD 4350/4550]

[Antoine Martin]

Please provide more details as per wiki/ReportingBugs, in particular your DE, xpra info captured when the problem occurs, etc

Does this also occur when you set --mmap=no?

[migration script]

this ticket has been moved to: ​https://github.com/Xpra-org/xpra/issues/2239