On Mon, 23 Nov 2020 15:46:56 GMT, Severin Gehwolf <sgehw...@openjdk.org> wrote:
> This is an enhancement which solves two issues:
>
> 1. Multiple reads of relevant cgroup interface files. Now interface files are
> only read once per file (just like Hotspot).
> 2. Proxies creation of the impl specific subsystem via `determineType()` as
> before, but now reads all relevant interface files: `/proc/cgroups`,
> `/proc/self/mountinfo` and `/proc/self/cgroup`. Once read it passes the
> parsed information to the impl specific subsystem classes for instantiation.
> This allows for more flexibility of testing as interface files can be mocked
> and, thus, more cases can be tested that way without having access to these
> specific systems. For example, proper regression tests for JDK-8217766 and
> JDK-8253435 have been added now with this in place.
>
> * [x] Tested on Linux x86_64 on cgroups v1 and cgroups v2. Container tests
> pass.
test/jdk/jdk/internal/platform/cgroup/TestCgroupSubsystemFactory.java line 238:
> 236: assertFalse("Join controller combination expected as cgroups
> v1", res.isCgroupV2());
> 237: CgroupInfo memoryInfo = res.getInfos().get("memory");
> 238: assertEquals("/user.slice/user-1000.slice/session-3.scope",
> memoryInfo.getCgroupPath());
The gist of the Java equivalent of JDK-8253939 (which fixed this for Hotspot).
I.e. a regression test for JDK-8217766 and JDK-8254854.
test/jdk/jdk/internal/platform/cgroup/TestCgroupSubsystemFactory.java line 267:
> 265: assertFalse("Duplicate cpusets should not influence detection
> heuristic", res.isCgroupV2());
> 266: CgroupInfo cpuSetInfo = res.getInfos().get("cpuset");
> 267: assertEquals("/sys/fs/cgroup/cpuset",
> cpuSetInfo.getMountPoint());
We can now assert the proper mount point is being used for multiple cpuset
mounts.
-------------
PR: https://git.openjdk.java.net/jdk/pull/1393
