Bug 1713023

+++ This bug was initially created as a clone of Bug #1713021 +++

Description of problem:

If CPUAccounting is enabled sbd isn't able to set rt-priority for its processes.


Version-Release number of selected component (if applicable):

1.3.1-18.el8


How reproducible:

100%

Steps to Reproduce:
1. Setup a cluster that uses sbd
2. Prior to starting cluster on one node (corosync and sbd still down) issue:
   'systemctl --runtime set-property system.slice CPUAccounting=true'
3. systemctl start pacemaker

Actual results:

'systemctl status sbd' prints
...
May 22 18:48:15 node4 sbd[2398]:    error: sbd_make_realtime: Unable to set scheduler priority to 99: Operation not permitted (1)
...

Using top or ps one can as well verify that the sbd-processes aren't rt scheduled.


Expected results:

sbd-processes should be rt-schedules as expected.

[root@node2 ~]# top -b|grep sbd
 1218 root      rt   0  126332  19952  18192 S   0.0   1.1   0:00.00 sbd
 1219 root      rt   0  142116  33448  29580 S   0.0   1.8   0:00.15 sbd
 1220 root      rt   0  142616  35992  30600 S   0.0   2.0   0:00.02 sbd


Additional info:

Amongst those components that enable CPUAccounting are e.g.
Red Hat Insights, Docker, ...

--- Additional comment from Klaus Wenninger on 2019-05-22 17:19:09 UTC ---

This could as well be assigned to e.g. systemd or another basic configuration component.
The discussion of this topic is controversial and it doesn't look as if there would be a clean and easy to access solution anytime soon.
Corosync meanwhile has gone a slightly hacky approach for the same problem.
This it probably makes sense to target a similar implementation in sbd as well to first have a solution that doesn't require additional configuration and to be consistent within the cluster-suite.