8253029: [PPC64] Remove obsolete Power6 code

[TheRealMDoerr]

The recent PPC64 platform files still contain code which is part of a Power6 optimization called Power6Scheduler. However, this functionality was never completely contributed so it was never usable in the OpenJDK.
We should remove it since we're no longer optimizing for Power6.

---

Progress

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

Issue

• JDK-8253029: [PPC64] Remove obsolete Power6 code

Reviewers

• David Holmes (@dholmes-ora - Reviewer) ⚠️ Review applies to a4e2ecffa199a454a5cebb07147e768ab2ad855d

Download

$ git fetch https://git.openjdk.java.net/jdk pull/116/head:pull/116
$ git checkout pull/116

[bridgekeeper]

👋 Welcome back mdoerr! 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]

⚠️ @TheRealMDoerr a branch with the same name as the source branch for this pull request (master) is present in the target repository. If you eventually integrate this pull request then the branch master in your personal fork will diverge once you sync your personal fork with the upstream repository.

To avoid this situation, create a new branch for your changes and reset the master branch. You can do this by running the following commands in a local repository for your personal fork. Note: you do not have to name the new branch NEW-BRANCH-NAME.

$ git checkout -b NEW-BRANCH-NAME
$ git branch -f master 418e4a259c8ba02c5d7a3cc0124f9e8980dc9c8e
$ git push -f origin master

Then proceed to create a new pull request with NEW-BRANCH-NAME as the source branch and close this one.

[openjdk]

@TheRealMDoerr The following label will be automatically applied to this pull request: hotspot.

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 (add|remove) "label" command.

[mlbridge]

Webrevs

• 02: Full - Incremental (ff21696)
• 01: Full - Incremental (f820714a28f002b4d3521dfebd6d737ab95f6ded)
• 00: Full (a4e2ecffa199a454a5cebb07147e768ab2ad855d)

[mlbridge]

Mailing list message from John Paul Adrian Glaubitz on hotspot-dev:

On 9/10/20 9:59 PM, Martin Doerr wrote:

The recent PPC64 platform files still contain code which is part of a Power6 optimization called Power6Scheduler.
However, this functionality was never completely contributed so it was never usable in the OpenJDK. We should remove it
since we're no longer optimizing for Power6.

I love that it has German comments in the code:

"// Schleife 1" ;-)

Adrian

--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer - glaubitz at debian.org
`. `' Freie Universitaet Berlin - glaubitz at physik.fu-berlin.de
`- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913

[dholmes-ora]

Code changes seem fine but this will need a CSR request as the flags are product flags. The CSR request can argue for immediate obsoletion (will need to be added to flags table in arguments.cpp) or even expiry (as per current webrev).

[dholmes-ora]

/csr needed

[openjdk]

@TheRealMDoerr This change now passes all automated pre-integration checks. In addition to the automated checks, the change must also fulfill all project specific requirements

After integration, the commit message will be:

8253029: [PPC64] Remove obsolete Power6 code

Reviewed-by: dholmes

• If you would like to add a summary, use the /summary command.
• To credit additional contributors, use the /contributor command.
• To add additional solved issues, use the /issue command.

Since the source branch of this PR was last updated there have been 6 commits pushed to the master branch:

• 8777ded: 8253008: Remove develop flags TraceLongCompiles/LongCompileThreshold
• c7062dc: 8253026: Remove dummy call to gc alot from VM Thread
• 5144190: 8243208: Clean up JVMFlag implementation
• 976acdd: 8252406: Introduce Thread::as_Java_thread() convenience function
• 4880226: 8171303: sun/java2d/pipe/InterpolationQualityTest.java fails on Windows & Linux
• 8da6c8d: 7183828: Invalid Image Variant when using anything other than BufferedImage

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid automatic rebasing, please merge master into your branch, and then specify the current head hash when integrating, like this: /integrate 8777ded1238ad195c6b1b63f54fa51984f8c95e4.

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

[openjdk]

@dholmes-ora has indicated that a compatibility and specification (CSR) request is needed for this pull request.
@TheRealMDoerr please create a CSR request and add link to it in JDK-8253029. This pull request cannot be integrated until the CSR request is approved.

[TheRealMDoerr]

Sorry, folks, I had to create a new PR because I had forgotten to create a branch. CSR is created. New PR contains Copyright update.

[mlbridge]

Mailing list message from David Holmes on hotspot-dev:

Something got messed up here. So for the mailing list record this PR was
cancelled not integrated! And now idea how the 8252817 info got included
here ???

David

On 11/09/2020 8:20 pm, Martin Doerr wrote: