OperatingSystemImpl.getCpuLoad() may return 1.0 in a container, even though the CPU load is obviously below 100%.
We created a 5-core container and run 4 "while (true)" loops in the container. OperatingSystemImpl.getCpuLoad() returned 1.0, which is incorrect (0.8 is correct). "systemLoad" in getCpuLoad() is exactly 4.0 before "systemLoad = Math.min(1.0, systemLoad);". The problem is caused by using the elapsed time (specified by "cpu.cfs_period_us") instead of the total CPU time (specified by "cpu.cfs_quota_us"). Therefore, it is more reasonable to divide cpu usage time by "quotaNanos" instead of "elapsedNanos". ------------- Commit messages: - 8265836: OperatingSystemImpl.getCpuLoad() returns incorrect CPU load Changes: https://git.openjdk.java.net/jdk/pull/3656/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3656&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8265836 Stats: 4 lines in 1 file changed: 0 ins; 1 del; 3 mod Patch: https://git.openjdk.java.net/jdk/pull/3656.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/3656/head:pull/3656 PR: https://git.openjdk.java.net/jdk/pull/3656
