> 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".
Hao Tang has updated the pull request incrementally with two additional commits since the last revision: - Use historical-value-based formula for both cpu-quota-based and cpu-shares-based calculation - rename usageTicks and totalTicks ------------- Changes: - all: https://git.openjdk.java.net/jdk/pull/3656/files - new: https://git.openjdk.java.net/jdk/pull/3656/files/c7abec03..eba3bc10 Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3656&range=05 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3656&range=04-05 Stats: 81 lines in 1 file changed: 32 ins; 39 del; 10 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
