8232782: Shenandoah: streamline post-LRB CAS barrier (aarch64)

[shipilev]

Unclean backport to improve Shenandoah AArch64 performance and provide grounds for subsequent backports.

There were conflicts in shenandoah_aarch64.ad, as there is weakCompareAndSwapPAcq_shenandoah and weakCompareAndSwapNAcq_shenandoah are missing in 11u.

Additional testing:

• Linux AArch64 hotspot_gc_shenandoah
• Linux AArch64 tier1 with -XX:+UseShenandoahGC
• Linux AArch64 tier2 with -XX:+UseShenandoahGC
• Linux AArch64 jcstress -m quick with -XX:+UseShenandoahGC

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change must be properly reviewed

Issue

• JDK-8232782: Shenandoah: streamline post-LRB CAS barrier (aarch64)

Reviewers

• Paul Hohensee (@phohensee - Reviewer)
• Roman Kennke (@rkennke - Committer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk11u-dev pull/268/head:pull/268
$ git checkout pull/268

Update a local copy of the PR:
$ git checkout pull/268
$ git pull https://git.openjdk.java.net/jdk11u-dev pull/268/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 268

View PR using the GUI difftool:
$ git pr show -t 268

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk11u-dev/pull/268.diff

[bridgekeeper]

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[openjdk]

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

[mlbridge]

Webrevs

• 00: Full (66fc5fe4)

[openjdk]

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

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

8232782: Shenandoah: streamline post-LRB CAS barrier (aarch64)

Reviewed-by: phh, rkennke

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 21 new commits pushed to the master branch:

• 13ddf0e: 8261072: AArch64: Fix MacroAssembler::get_thread convention
• 4699467: 8248816: C1: Fix signature conflict in LIRGenerator::strength_reduce_multiply
• 4a3afd7: 8248657: Windows: strengthening in ThreadCritical regarding memory model
• 8afb159: 8250824: AArch64: follow up for JDK-8248414
• 6a6e00e: 8255790: GTKL&F: Java 16 crashes on initialising GTKL&F on Manjaro Linux
• 83d916e: 8272772: Shenandoah: compiler/c2/aarch64/TestVolatilesShenandoah.java fails in 11u
• 417b388: 8272472: StackGuardPages test doesn't build with glibc 2.34
• a27ee49: 8270096: Shenandoah: Optimize gc/shenandoah/TestRefprocSanity.java for interpreter mode
• 4a2cd36: 8252853: AArch64: gc/shenandoah/TestVerifyJCStress.java fails intermittently with C1
• 519894a: 8269478: Shenandoah: gc/shenandoah/mxbeans tests should be more resilient
• ... and 11 more: https://git.openjdk.java.net/jdk11u-dev/compare/8f402b26c164241b0ac705a5c42c80c646872fe7...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.

[shipilev]

Thank you, @phh! @rkennke, do you have any concerns with this patch?

[rkennke]

Looks good to me, thanks!!

[shipilev]

Got the push approvals and reviews.

/integrate

[openjdk]

Going to push as commit fb886e9.
Since your change was applied there have been 24 commits pushed to the master branch:

• 5a539db: 8249548: backward focus traversal gets stuck in button group
• da90fbb: 8265756: AArch64: initialize memory allocated for locals according to Windows AArch64 stack page growth requirement in template interpreter
• f334c2e: 8263136: C4530 was reported from VS 2019 at access bridge
• 13ddf0e: 8261072: AArch64: Fix MacroAssembler::get_thread convention
• 4699467: 8248816: C1: Fix signature conflict in LIRGenerator::strength_reduce_multiply
• 4a3afd7: 8248657: Windows: strengthening in ThreadCritical regarding memory model
• 8afb159: 8250824: AArch64: follow up for JDK-8248414
• 6a6e00e: 8255790: GTKL&F: Java 16 crashes on initialising GTKL&F on Manjaro Linux
• 83d916e: 8272772: Shenandoah: compiler/c2/aarch64/TestVolatilesShenandoah.java fails in 11u
• 417b388: 8272472: StackGuardPages test doesn't build with glibc 2.34
• ... and 14 more: https://git.openjdk.java.net/jdk11u-dev/compare/8f402b26c164241b0ac705a5c42c80c646872fe7...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit fb886e9.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.