TTY-based group scheduling [LWN.net]

TTY-based group scheduling

Posted Nov 18, 2010 13:14 UTC (Thu) by iq-0 (subscriber, #36655)
Parent article: TTY-based group scheduling

TTY is just being used as a heuristic in this case. Why not mirror the process-tree or build a process-group-tree?
This could even be applied more generically in other schemes (systemd creating a cgroup and subgroups are automagically created within their parents group).

But I fear cgroups don't scale to 1 level per process/process-group. Otherwise I think this would automagically work for all users (eg. running chrome (multiprocess possibly cpu hog) a game and listing to some music in another app instead of the in-game music).

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TTY-based group scheduling

Posted Nov 18, 2010 21:09 UTC (Thu) by jzbiciak (✭ supporter ✭, #5246) [Link]

Yeah, I'm skeptical that assigning groups by TTY is the way to go for the average user. For folks like me with 50-bazillion terminal windows open trying to multitask while running lots of compute? Yeah, sure. For someone who has never opened a terminal window? I can't see how it could possibly help.

For giggles, I just logged into my wife's computer remotely over ssh. Out of ~167 processes, only 10 had controlling terminals. 6 were idle gettys on tty1-6, 1 was Xorg on tty7, and the other 3 were processes associated with my ssh session. What process group(s) would all the other 150+ tasks be assigned to? Or all they all effectively in their own per-process groups by default? How would this patch benefit users like my wife, who open few if any interactive sessions?

It also breaks if you're the type that launches a bunch of GUI apps in the background from the same shell window. They might all inherit the same TTY but never use it. Now they'd get lumped in the same group.

TTY-based group scheduling

Posted Nov 20, 2010 1:39 UTC (Sat) by sayap (guest, #71380) [Link]

Con Kolivas has developed a hierarchical tree-based penalty patch and has since dropped it, because desktop doesn't need more heuristics. Read more here: http://ck-hack.blogspot.com/2010/11/create-task-groups-by...