On Wed 20-09-23 01:11:01, Jeremi Piotrowski wrote: > On Sun, Sep 17, 2023 at 09:12:40PM +0200, Greg Kroah-Hartman wrote: > > 6.1-stable review patch. If anyone has any objections, please let me know. > > > > ------------------ > > Hi Greg/Michal, > > This commit breaks userspace which makes it a bad commit for mainline and an > even worse commit for stable. > > We ingested 6.1.54 into our nightly testing and found that runc fails to gather > cgroup statistics (when reading kmem.limit_in_bytes). The same code is vendored > into kubelet and kubelet fails to start if this operation fails. 6.1.53 is > fine. Could you expand some more on why is the file read? It doesn't support writing to it for some time so how does reading it helps in any sense? Anyway, I do agree that the stable backport should be reverted. > > Address this by wiping out the file completely and effectively get back to > > pre 4.5 era and CONFIG_MEMCG_KMEM=n configuration. > > On reads, the runc code checks for MEMCG_KMEM=n by checking > kmem.usage_in_bytes. If it is present then runc expects the other cgroup files > to be there (including kmem.limit_in_bytes). So this change is not effectively > the same. > > Here's a link to the PR that would be needed to handle this change in userspace > (not merged yet and would need to be propagated through the ecosystem): > > https://github.com/opencontainers/runc/pull/4018. Thanks. Does that mean the revert is still necessary for the Linus tree or do you expect that the fix can be merged and propagated in a reasonable time? -- Michal Hocko SUSE Labs
