RFR: 8326446: The User and System of jdk.CPULoad on Apple M1 are inaccurate [v2]

[Long Yang]

On Wed, 28 Feb 2024 11:46:35 GMT, Markus Grönlund <mgronlun at openjdk.org> wrote:

> Seems reasonable.
> 
> Is there a risk of introducing a regression for existing platforms? Did the result on x64 turn out equivalent to pre-change?

I ran the pre- and post-change versions on MacOS X64, and I can see that the results are consistent.

OS Information

Time     OS Version
-------- --------------------------------------------------------------------------------------------------------------
22:28:13 uname: Darwin 21.6.0 Darwin Kernel Version 21.6.0: Mon Apr 24 21:10:53 PDT 2023; root:xnu-8020.240.18.701.5...

CPU Information

Time     Type                                    Description                             Sockets Cores Hardware Threads
-------- --------------------------------------- --------------------------------------- ------- ----- ----------------
22:28:13 Intel Haswell (HT) SSE SSE2 SSE3 SSS... Brand: Intel(R) Core(TM) i7-4770HQ C...       1     4                8

                                     CPU Load (pre fix, I ran the changed version first, so the time is newer)

Time                         JVM User           JVM System           Machine Total
------------------ ------------------ -------------------- -----------------------
22:28:15                       10.41%               39.19%                  76.21%
22:28:16                       10.31%               39.46%                  70.88%
22:28:17                       10.30%               39.46%                  68.58%
22:28:18                       10.30%               39.47%                  67.96%

                                     CPU Load (post fix)

Time                         JVM User           JVM System           Machine Total
------------------ ------------------ -------------------- -----------------------
22:25:58                       10.40%               38.99%                  82.34%
22:25:59                       10.37%               39.50%                  82.15%
22:26:00                       10.27%               39.23%                  68.65%
22:26:01                       10.37%               39.63%                  68.25%

-------------

PR Comment: https://git.openjdk.org/jdk/pull/17976#issuecomment-1969134580