8247469: getSystemCpuLoad() returns -1 on linux when some offline cpus are present and cpusets.effective_cpus is not available

[jerboaa]

Please review this backport for OpenJDK 11u. For one it fixes a bug where wrong cpuload is being reported when there are not all CPUs on the host online, and for two is a preparatory backport for JDK-8265836.

The patch doesn't apply cleanly. The only difference is in context of the if condition in isCpuSetSameAsHostCpuSet(). In JDK 17 there is an additional null check for what containerMetrics.getCpuSetCpus() returns. This is not needed in 11u since it doesn't have JDK-8231111 (adds cgroups v2 support) which changes containerMetrics.getCpuSetCpus() to potentially return null for "not supported". That's not applicable in 11.

Thoughts?

---

Progress

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Issue

• JDK-8247469: getSystemCpuLoad() returns -1 on linux when some offline cpus are present and cpusets.effective_cpus is not available

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk11u-dev pull/9/head:pull/9
$ git checkout pull/9

Update a local copy of the PR:
$ git checkout pull/9
$ git pull https://git.openjdk.java.net/jdk11u-dev pull/9/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 9

View PR using the GUI difftool:
$ git pr show -t 9

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk11u-dev/pull/9.diff

[bridgekeeper]

👋 Welcome back sgehwolf! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

This backport pull request has now been updated with issue from the original commit.

[openjdk]

@jerboaa This change now passes all automated pre-integration checks.

After integration, the commit message for the final commit will be:

8247469: getSystemCpuLoad() returns -1 on linux when some offline cpus are present and cpusets.effective_cpus is not available

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

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[mlbridge]

Webrevs

• 00: Full (b252ff4b)

[jerboaa]

/integrate

[openjdk]

@jerboaa Since your change was applied there have been 9 commits pushed to the master branch:

• 6deb21f: 8196092: javax/swing/JComboBox/8032878/bug8032878.java fails
• d3a5ed2: 8267773: PhaseStringOpts::int_stringSize doesn't handle min_jint correctly
• f55ef1e: 8210495: compiler crashes because of illegal signature in otherwise legal code
• e6d0e9d: 8266642: Improve ResolvedMethodTable hash function
• 5c35022: 8211296: Remove HotSpot deprecation warning suppression for Mac/clang
• 006979a: 8257148: Remove obsolete code in AWTView.m
• be0b9b1: 8266615: C2 incorrectly folds subtype checks involving an interface array
• ab9d3de: 8261652: Remove some dead comments from os_bsd_x86
• 09d3082: 8265231: (fc) ReadDirect and WriteDirect tests fail after fix for JDK-8264821

Your commit was automatically rebased without conflicts.

Pushed as commit 624e91b.

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