> An issue similar to > [JDK-8239559](https://bugs.openjdk.java.net/browse/JDK-8239559) has been > discovered. On the > affected system, `/proc/self/mountinfo` contains a line such as this one: > > 35 26 0:26 / /sys/fs/cgroup/systemd rw,nosuid,nodev,noexec,relatime - cgroup > systemd rw,name=systemd > > > Note that `/proc/cgroups` looks like this: > > #subsys_name hierarchy num_cgroups enabled > cpuset 0 1 1 > cpu 0 1 1 > cpuacct 0 1 1 > blkio 0 1 1 > memory 0 1 1 > devices 0 1 1 > freezer 0 1 1 > net_cls 0 1 1 > perf_event 0 1 1 > net_prio 0 1 1 > hugetlb 0 1 1 > pids 0 1 1 > > This is in fact a cgroups v1 system with systemd put into a separate > namespace via FS type `cgroup`. That mountinfo > line confuses the cgroups version detection heuristic. It only looked whether > or not there is **any** entry in > mountinfo of FS-type `cgroup` . That's wrong. A better heuristic would be > looking at controllers we care about: `cpu`, > `cpuacct`, `memory`, `cpuset` for hotspot and some more for the Java side. > The proposed fix on the hotspot side is to > set `any_cgroup_mounts_found` to true only if one of those controllers show > up in mountinfo. Otherwise, we know it's > cgroup v2 due to the zero hierarchy ids. The fix on the Java side is similar. > For the Java side the proposal is also > to do the parsing of the cgroup files in the factory now (single pass of > files). No longer in the version specific > objects. In order to not regress here, I've added more tests. > **Testing** > > - [x] Linux x86_64 container tests on cgroup v1 (fastdebug) > - [x] Linux x86_64 container tests on cgroup v2 (fastdebug) > - [x] Added regression test which fails prior the patch and passes after > - [x] Submit testing
Severin Gehwolf has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR. The pull request contains one new commit since the last revision: 8245543: Cgroups: Incorrect detection logic on some systems (still reproducible) ------------- Changes: - all: https://git.openjdk.java.net/jdk/pull/485/files - new: https://git.openjdk.java.net/jdk/pull/485/files/5e2ca2dc..e72ac219 Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=485&range=04 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=485&range=03-04 Stats: 514 lines in 5 files changed: 159 ins; 231 del; 124 mod Patch: https://git.openjdk.java.net/jdk/pull/485.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/485/head:pull/485 PR: https://git.openjdk.java.net/jdk/pull/485
