8351655: Optimize ObjectMonitor::unlink_after_acquire()

[fbredber]

This PR implements an optimization of ObjectMonitor::unlink_after_acquire(). If it's possible it only converts the first part (the singly linked part) of the entry_list into a doubly linked list and leave the _entry_list_tail pointer untouched.

It has passed tier1-tier8 tests.

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8351655: Optimize ObjectMonitor::unlink_after_acquire() (Enhancement - P4)

Reviewers

• Coleen Phillimore (@coleenp - Reviewer) Review applies to 12581560
• Patricio Chilano Mateo (@pchilano - Reviewer)
• David Holmes (@dholmes-ora - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/24078/head:pull/24078
$ git checkout pull/24078

Update a local copy of the PR:
$ git checkout pull/24078
$ git pull https://git.openjdk.org/jdk.git pull/24078/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 24078

View PR using the GUI difftool:
$ git pr show -t 24078

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/24078.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back fbredberg! 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]

@fbredber 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:

8351655: Optimize ObjectMonitor::unlink_after_acquire()

Reviewed-by: pchilanomate, dholmes, coleenp

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 134 new commits pushed to the master branch:

• 0cb110e: 8350892: [JVMCI] Align ResolvedJavaType.getInstanceFields with Class.getDeclaredFields
• 04eac0c: 8352159: RISC-V: add more zfa support
• ac760dd: 8352423: RISC-V: simplify DivI/L ModI/L
• d1cf232: 8352248: Check if CMoveX is supported
• 2b55979: 8352529: RISC-V: enable loopopts tests
• 8469458: 8352511: Show additional level of headings in table of contents
• 28250f8: 8352151: Fix display issues in javadoc-generated docs
• b32be18: 8352178: Add precondition in VMThread::execute to prevent deadlock
• 07667ca: 8352506: Simplify make/test/JtregNativeHotspot.gmk
• b545b9e: 8352584: [Backout] G1: Pinned regions with pinned objects only reachable by native code crash VM
• ... and 124 more: https://git.openjdk.org/jdk/compare/cd9f1d3d921531511a7552807d099d5d3cce01a6...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.

[openjdk]

@fbredber The following label will be automatically applied to this pull request:

• hotspot-runtime

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

[mlbridge]

Webrevs

• 02: Full - Incremental (ccf1e7e0)
• 01: Full - Incremental (e6d1ed81)
• 00: Full (12581560)

[coleenp]

This looks really good.

[pchilano]

Thanks for taking care of this follow up. Looks good to me, just minor comments.

[dholmes-ora]

Generally okay but a few minor nits - plus Patricio's suggestion.

Thanks

[dholmes-ora]

A few more nits - plus I agree with Patricio's comments.

[dholmes-ora]

Nothing further from me. Thanks

[pchilano]

Thanks, looks good to me.

[fbredber]

Thanks for the reviews. I'll integrate after the weekend.

[fbredber]

/integrate

[openjdk]

Going to push as commit 45a9750.
Since your change was applied there have been 194 commits pushed to the master branch:

• 2e4d7d1: 8302459: Missing late inline cleanup causes compiler/vectorapi/VectorLogicalOpIdentityTest.java IR failure
• 1a8c8e0: 8352858: Make java.net.JarURLConnection fields final
• a81250c: 8352673: RISC-V: Vector can't be turned on with -XX:+UseRVV
• 0935ba9: 8352481: Enforce the use of lld with clang
• dbc620f: 8352299: GenShen: Young cycles that interrupt old cycles cannot be cancelled
• f5a0db4: 8315447: Invalid Type Annotation attached to a method instead of a lambda
• 60544a1: 8164714: Constructor.newInstance creates instance of inner class with null outer class
• c856b34: 8352587: C2 SuperWord: we must avoid Multiversioning for PeelMainPost loops
• 993eae4: 8346948: Update CLDR to Version 47.0
• e98838f: 8352065: [PPC64] C2: Implement PopCountVL, CountLeadingZerosV and CountTrailingZerosV nodes
• ... and 184 more: https://git.openjdk.org/jdk/compare/cd9f1d3d921531511a7552807d099d5d3cce01a6...master

Your commit was automatically rebased without conflicts.

[openjdk]

@fbredber Pushed as commit 45a9750.

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