Core scheduling lands in 5.14

Posted Jul 1, 2021 19:05 UTC (Thu) by bluca (subscriber, #118303)
Parent article: Core scheduling lands in 5.14

Is there any particular reason why this cannot be set at the cgroup level, rather than having yet-another-knob userspace has to deal with?

to post comments

Control groups

Posted Jul 1, 2021 19:07 UTC (Thu) by corbet (editor, #1) [Link] (6 responses)

I suspect they didn't want to force the use of control groups, but that's a guess.

Regardless, it's a knob to tweak either way, so I don't think that would change much.

Control groups

Posted Jul 1, 2021 20:23 UTC (Thu) by walters (subscriber, #7396) [Link] (5 responses)

See the linked article:

The patch set has seen a fair amount of discussion. Greg Kerr, representing Chrome OS, questioned the control-group interface. Making changes to control groups is a privileged operation, but he would like for unprivileged processes to be able to set their own cookies. To that end, he proposed an API based on ptrace() prctl() calls. Zijlstra replied that the interface issues can be worked out later; first it's necessary to get everything working as desired.

Personally I find this surprising because systemd already supports delegating cgroup access: https://systemd.io/CGROUP_DELEGATION/.

Control groups

Posted Jul 2, 2021 3:44 UTC (Fri) by Gaelan (guest, #145108) [Link] (4 responses)

It isn't very clear from a quick google, but I don't think Chrome OS uses systemd.

Control groups

Posted Jul 2, 2021 4:06 UTC (Fri) by rahulsundaram (subscriber, #21946) [Link] (3 responses)

> It isn't very clear from a quick google, but I don't think Chrome OS uses systemd.

Uses Upstart. They hired the primary developer and moved to it years back

https://www.chromium.org/chromium-os/chromiumos-design-do...

Control groups

Posted Jul 2, 2021 4:47 UTC (Fri) by re:fi.64 (subscriber, #132628) [Link]

Worth noting that I believe Container Linux images are based on Chrome OS but do use systemd.

Control groups

Posted Jul 2, 2021 4:53 UTC (Fri) by Cyberax (✭ supporter ✭, #52523) [Link] (1 responses)

There are patches (overlays) for Chromium OS that use systemd. Moreover, even the stock Chromium OS uses journald with upstart.

Control groups

Posted Jul 2, 2021 17:44 UTC (Fri) by bnorris (subscriber, #92090) [Link]

> even the stock Chromium OS uses journald with upstart.

No longer: https://crbug.com/1066706