On Mon, 23 May 2022 22:11:47 GMT, Ioi Lam <ik...@openjdk.org> wrote: > This PR fixes a bug found on an Ubuntu host that's mostly running with > cgroupv2, but there's a controller (freezer) that is mounted in cgroupv1 mode. > > The container support code in the VM and JDK checks if we have simultaneously > mounted v1 and v2 containers. If so, we revert to "hybrid" mode (which is > essentially v1). > > However, the "hybrid checks" only considers the following controllers that > Java cares about: > > - cpu > - cpuacct > - cpuset > - blkio > - memory > - pids > > If only "freezer" is mounted in v1 mode, Java will start in V2 mode. Later, > when `setCgroupV2Path()` sees the first line in /proc/self/cgroup, it runs > into the assert. > > > $ cat /proc/self/cgroup > 1:freezer:/ > 0::/user.slice/user-1001.slice/session-85.scope > > > The fix is simple -- when we get to `setCgroupV2Path()`, we have already > decided that the system has not mounted any v1 controllers that we care > about, so we should just ignore all the v1 controllers (which has a non-empty > name).
This pull request has now been integrated. Changeset: 704b9a66 Author: Ioi Lam <ik...@openjdk.org> URL: https://git.openjdk.java.net/jdk/commit/704b9a66bba0dc8adb62be80fd62864b9c687c3f Stats: 117 lines in 3 files changed: 114 ins; 0 del; 3 mod 8287107: CgroupSubsystemFactory.setCgroupV2Path asserts with freezer controller Reviewed-by: mseledtsov, sgehwolf ------------- PR: https://git.openjdk.java.net/jdk/pull/8858
