8321269: Require platforms to define DEFAULT_CACHE_LINE_SIZE

[shipilev]

Found it while doing new code that wants to know the cache line size. Currently, there is a fallback in globalDefinitions.hpp that defaults DEFAULT_CACHE_LINE_SIZE to 64 if platform does not define it. Instead of relying on default, force platform definitions to tell what is the reasonable default for the platform. This would simplify porting to other architectures, with less surprises for them.

The actual sizes do not change. If any existing platform needs adjustments, those should be handled as separate issues.

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Issue

• JDK-8321269: Require platforms to define DEFAULT_CACHE_LINE_SIZE (Enhancement - P4)

Reviewers

• Stefan Karlsson (@stefank - Reviewer)
• Thomas Stuefe (@tstuefe - Reviewer)
• David Holmes (@dholmes-ora - Reviewer)

Reviewing

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[mlbridge]

Webrevs

• 00: Full (d1419b35)

[stefank]

Seems reasonable to me.

[openjdk]

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

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

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

8321269: Require platforms to define DEFAULT_CACHE_LINE_SIZE

Reviewed-by: stefank, stuefe, dholmes

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

At the time when this comment was updated there had been 67 new commits pushed to the master branch:

• 50d1839: 8318809: java/util/concurrent/ConcurrentLinkedQueue/WhiteBox.java shows intermittent failures on linux ppc64le and aarch64
• 81484d8: 8320687: sun.jvmstat.monitor.MonitoredHost.getMonitoredHost() throws unexpected exceptions when invoked concurrently
• 30b5d42: 8321069: JvmtiThreadState::state_for_while_locked() returns nullptr for an attached JNI thread with a java.lang.Thread object after JDK-8319935
• bd04f91: 8321131: Console read line with zero out should zero out underlying buffer in JLine
• 155abc5: 8311906: Improve robustness of String constructors with mutable array inputs
• 316b783: 8321276: runtime/cds/appcds/dynamicArchive/DynamicSharedSymbols.java failed with "'17 2: jdk/test/lib/apps ' missing from stdout/stderr"
• 65be5e0: 8305931: jdk/jfr/jcmd/TestJcmdDumpPathToGCRoots.java failed with "Expected chains but found none"
• f6be922: 8316193: jdk/jfr/event/oldobject/TestListenerLeak.java java.lang.Exception: Could not find leak
• a9de5c7: 8315128: jdk/jfr/event/runtime/TestResidentSetSizeEvent.java fails with "The size should be less than or equal to peak"
• d2c529c: 8319072: JFR: Turn off events for JFR.view
• ... and 57 more: https://git.openjdk.org/jdk/compare/d6b4aa01a20eb7ecd44602a9fab3e3380bff3d3a...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[tstuefe]

+1

[dholmes-ora]

Seems fine to me too.

[shipilev]

Thanks all!

/integrate

[openjdk]

Going to push as commit a56286f.
Since your change was applied there have been 70 commits pushed to the master branch:

• 1cf7ef5: 8321273: Parallel: Remove unused UpdateOnlyClosure::_space_id
• 517b178: 8306914: Implement JEP 458: Launch Multi-File Source-Code Programs
• aec3865: 8320697: RISC-V: Small refactoring for runtime calls
• 50d1839: 8318809: java/util/concurrent/ConcurrentLinkedQueue/WhiteBox.java shows intermittent failures on linux ppc64le and aarch64
• 81484d8: 8320687: sun.jvmstat.monitor.MonitoredHost.getMonitoredHost() throws unexpected exceptions when invoked concurrently
• 30b5d42: 8321069: JvmtiThreadState::state_for_while_locked() returns nullptr for an attached JNI thread with a java.lang.Thread object after JDK-8319935
• bd04f91: 8321131: Console read line with zero out should zero out underlying buffer in JLine
• 155abc5: 8311906: Improve robustness of String constructors with mutable array inputs
• 316b783: 8321276: runtime/cds/appcds/dynamicArchive/DynamicSharedSymbols.java failed with "'17 2: jdk/test/lib/apps ' missing from stdout/stderr"
• 65be5e0: 8305931: jdk/jfr/jcmd/TestJcmdDumpPathToGCRoots.java failed with "Expected chains but found none"
• ... and 60 more: https://git.openjdk.org/jdk/compare/d6b4aa01a20eb7ecd44602a9fab3e3380bff3d3a...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit a56286f.

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