Bug 1713021
| Summary: | sbd is unable to set rt-priority if CPUAccounting is enabled | |||
|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 8 | Reporter: | Klaus Wenninger <kwenning> | |
| Component: | sbd | Assignee: | Klaus Wenninger <kwenning> | |
| Status: | CLOSED ERRATA | QA Contact: | cluster-qe <cluster-qe> | |
| Severity: | unspecified | Docs Contact: | ||
| Priority: | unspecified | |||
| Version: | 8.0 | CC: | cfeist, cluster-maint, mlisik, mmazoure, sbradley | |
| Target Milestone: | rc | Flags: | pm-rhel:
mirror+
|
|
| Target Release: | 8.1 | |||
| Hardware: | Unspecified | |||
| OS: | Unspecified | |||
| Whiteboard: | ||||
| Fixed In Version: | sbd-1.4.0-8.el8 | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | ||
| Clone Of: | ||||
| : | 1713023 1715134 (view as bug list) | Environment: | ||
| Last Closed: | 2019-11-05 20:46:42 UTC | Type: | Bug | |
| Regression: | --- | Mount Type: | --- | |
| Documentation: | --- | CRM: | ||
| Verified Versions: | Category: | --- | ||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | ||
| Cloudforms Team: | --- | Target Upstream Version: | ||
| Embargoed: | ||||
| Bug Depends On: | ||||
| Bug Blocks: | 1713023, 1715134, 1715136 | |||
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Description
Klaus Wenninger
2019-05-22 17:12:12 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. Guess I've found a viable extension to the way how corosync is tackling the issue atm
that should be more compatible with the current behaviour especially in cases
where a setup has already introduced something like a realtime.slice that already
has some rt-budget assigned.
Configuration for it will reside in /etc/sysconfig/sbd:
## Type: yesno / auto
## Default: auto
#
# If CPUAccounting is enabled default is not to assign any RT-budget
# to the system.slice which prevents sbd from running RR-scheduled.
#
# One way to escape that issue is to move sbd-processes from the
# slice they were originally started to root-slice.
# Of course starting sbd in a certain slice might be intentional.
# Thus in auto-mode sbd will check if the slice has RT-budget assigned.
# If that is the case sbd will stay in that slice while it will
# be moved to root-slice otherwise.
SBD_MOVE_TO_ROOT_CGROUP=auto
As selinux-rules are quite fine-grained with sbd there are some
additions to the rules required:
For moving to root-slice sbd will need ro access to
- /sys/fs/cgroup/cpu/cpu.rt_runtime_us
and write access to
- /sys/fs/cgroup/cpu/tasks.
For checks needed for the auto-mode additional ro access
is required for
- /proc/${pid}/cgroup
and
- /sys/fs/cgroup/cpu/${slice}/cpu.rt_runtime_us
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2019:3344 |