Bug 1756143
| Summary: | after running 'mock', /proc/self/cgroup contains name=systemd. intentional? | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Cole Robinson <crobinso> |
| Component: | systemd | Assignee: | systemd-maint |
| Status: | CLOSED ERRATA | QA Contact: | Fedora Extras Quality Assurance <extras-qa> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 31 | CC: | ego.cordatus, lnykryn, msekleta, praiskup, ssahani, s, systemd-maint, vascom2, yaneti, zbyszek |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | systemd-243-3.gitef67743.fc31 | Doc Type: | If docs needed, set a value |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2019-10-26 17:24:42 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: | |||
|
Description
Cole Robinson
2019-09-26 20:45:45 UTC
mock doesn't matter here, plain systemd-nspawn invocation is enough to cause this (with the right image). systemd-nspawn has code to detect if the image it is about to start has an init that has support for the unified cgroup hierarchy. Specifically, it checks if systemd>230 is installed. If it detects no support, if falls back to mounting legacy hierarchy. This is a bit ugly, but in the beginning almost nothing had support for the unified hierarchy, and we didn't want to break spawning of existing images. Maybe this should be revisited, but I don't think there's any easy solution if we want to keep compatibility with older images. With recent buildroot dependency cleanups, systemd may no longer be installed by mock, so suddenly systemd-nspawn detects no support and falls back to legacy in the booted image. Once that happens, I don't think it is possible to undo without rebooting. It is possible to override the detection by setting UNIFIED_CGROUP_HIERARCHY=yes. You can use that as a temporary work-around. That said, mock actually calls systemd-nspawn with --as-pid2/-a. In this mode, nspawn "knows" that a compatible init will be running (because it is it), so we should skip the detection based on the image. I'll prep a patch. FEDORA-2019-5cb48e5111 has been submitted as an update to Fedora 31. https://bodhi.fedoraproject.org/updates/FEDORA-2019-5cb48e5111 systemd-243-3.gitef67743.fc31 has been pushed to the Fedora 31 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2019-5cb48e5111 RHBZ#1756143 not fixed. I did ~40 builds and now it hangs again. @Artem: This bug is about a very simple thing: whether 'systemd-nspawn --as-pid2' mounts v1 or v2 hierarchy in the container. It is fully deterministic, without any race conditions, so if you're seeing hangs when doing a large number of builds, then it's most likely some different thing. Oh, sorry. Maybe we should reopen #1754807 then? https://bugzilla.redhat.com/show_bug.cgi?id=1754807 @Vascom wrote that it still happens as well. #1754807 still persist. systemd-243-3.gitef67743.fc31 has been pushed to the Fedora 31 stable repository. If problems still persist, please make note of it in this bug report. |