8299844: RISC-V: Implement _onSpinWait intrinsic #11921

yadongw · 2023-01-10T09:52:40Z

Implement _onSpinWait() intrinsic for RISC-V, and it can be implemented by using PAUSE instruction from Zihintpause Extension, which is ratified and a mandatory extension of RVA22U64 (https://github.com/riscv/riscv-profiles/blob/main/profiles.adoc#rva22u64-mandatory-extensions).
Software can use the PAUSE instruction to reduce energy consumption while executing spinwait
code sequences (https://github.com/riscv/riscv-isa-manual/blob/master/src/zihintpause.tex).

Add a test case of test/hotspot/jtreg/compiler/onSpinWait/TestOnSpinWaitRISCV64.java, passed on QEMU.

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-8299844: RISC-V: Implement _onSpinWait intrinsic

Reviewers

Feilong Jiang (@feilongjiang - Author)
Fei Yang (@RealFYang - Reviewer)
Ludovic Henry (@luhenry - Committer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk pull/11921/head:pull/11921
$ git checkout pull/11921

Update a local copy of the PR:
$ git checkout pull/11921
$ git pull https://git.openjdk.org/jdk pull/11921/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 11921

View PR using the GUI difftool:
$ git pr show -t 11921

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/11921.diff

bridgekeeper · 2023-01-10T09:54:36Z

👋 Welcome back yadongwang! 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 · 2023-01-10T09:58:05Z

@yadongw 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 pull request command.

mlbridge · 2023-01-11T08:20:17Z

Webrevs

feilongjiang

Looks good, with some comments:

feilongjiang · 2023-01-11T12:34:24Z

test/hotspot/jtreg/compiler/onSpinWait/TestOnSpinWaitRISCV64.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.


Copyright here is Amazon.

feilongjiang · 2023-01-11T12:37:08Z

src/hotspot/cpu/riscv/assembler_riscv.hpp

    emit(insn);
  }

+  void pause() {


#10697 moved all pseudo instructions to macroAssembler, I think pause should be defined in there too.

luhenry · 2023-01-11T17:23:13Z

src/hotspot/cpu/riscv/riscv.ad

@@ -1815,6 +1816,8 @@ const bool Matcher::match_rule_supported(int opcode) {
  }

  switch (opcode) {
+    case Op_OnSpinWait:
+      return VM_Version::supports_on_spin_wait();


You can use UseZihintpause directly just like for UseRVV, UsePopCountInstruction, or UseZbb below.

supports_on_spin_wait() is called both from share and cpu specific code. I think it's better to be a unified switch.

RealFYang

Don't forget to update the copyright year of the changes files.

feilongjiang · 2023-01-15T04:29:56Z

src/hotspot/cpu/riscv/assembler_riscv.cpp

@@ -1,7 +1,7 @@
 /*
 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2014, Red Hat Inc. All rights reserved.
- * Copyright (c) 2020, 2022, Huawei Technologies Co., Ltd. All rights reserved.


Unnecessary copyright year update of asembler_riscv.cpp.

RealFYang

Looks fine to me.

openjdk · 2023-01-17T13:27:22Z

@yadongw 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:

8299844: RISC-V: Implement _onSpinWait intrinsic

Reviewed-by: fjiang, fyang, luhenry

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 332 new commits pushed to the master branch:

5dfc4ec: 8300140: ZipFile.isSignatureRelated returns true for files in META-INF subdirectories
5c59de5: Merge
e5860ef: 8301206: Fix issue with LocaleData after JDK-8300719
b22e521: 8300953: ClassDesc::ofInternalName missing @SInCE tag
a67b1e7: 8300719: JDK 20 RDP2 L10n resource files update
ae0e76d: 8301120: Cleanup utility classes java.util.Arrays and java.util.Collections
b8e5abc: 8301097: Update GHA XCode to 12.5.1
9c4bc2c: 8301132: Test update for deprecated sprintf in Xcode 14
7f05d57: 8217920: Lookup.defineClass injects a class that can access private members of any class in its own module
22c976a: 8177418: NPE is not apparent for methods in java.util.TimeZone API docs
... and 322 more: https://git.openjdk.org/jdk/compare/195f31371f4612a2d9d12a83deb281698ff68bfb...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.

As you do not have Committer status in this project an existing Committer must agree to sponsor your change. Possible candidates are the reviewers of this PR (@RealFYang, @luhenry) but any other Committer may sponsor as well.

➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

yadongw · 2023-01-28T01:10:03Z

/integrate

openjdk · 2023-01-28T01:11:43Z

@yadongw
Your change (at version 295fa7c) is now ready to be sponsored by a Committer.

RealFYang · 2023-01-28T02:15:49Z

/sponsor

openjdk · 2023-01-28T02:17:53Z

Going to push as commit af564e4.
Since your change was applied there have been 332 commits pushed to the master branch:

5dfc4ec: 8300140: ZipFile.isSignatureRelated returns true for files in META-INF subdirectories
5c59de5: Merge
e5860ef: 8301206: Fix issue with LocaleData after JDK-8300719
b22e521: 8300953: ClassDesc::ofInternalName missing @SInCE tag
a67b1e7: 8300719: JDK 20 RDP2 L10n resource files update
ae0e76d: 8301120: Cleanup utility classes java.util.Arrays and java.util.Collections
b8e5abc: 8301097: Update GHA XCode to 12.5.1
9c4bc2c: 8301132: Test update for deprecated sprintf in Xcode 14
7f05d57: 8217920: Lookup.defineClass injects a class that can access private members of any class in its own module
22c976a: 8177418: NPE is not apparent for methods in java.util.TimeZone API docs
... and 322 more: https://git.openjdk.org/jdk/compare/195f31371f4612a2d9d12a83deb281698ff68bfb...master

Your commit was automatically rebased without conflicts.

openjdk · 2023-01-28T02:18:08Z

@RealFYang @yadongw Pushed as commit af564e4.

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

8299844: RISC-V: Implement _onSpinWait intrinsic

edce366

openjdk bot added the hotspot hotspot-dev@openjdk.org label Jan 10, 2023

fix whitespace

7d9861e

openjdk bot added the rfr Pull request is ready for review label Jan 11, 2023

feilongjiang suggested changes Jan 11, 2023

View reviewed changes

luhenry reviewed Jan 11, 2023

View reviewed changes

RealFYang suggested changes Jan 13, 2023

View reviewed changes

fix copyright year

4f8a526

feilongjiang reviewed Jan 15, 2023

View reviewed changes

fix copyright year

295fa7c

luhenry approved these changes Jan 17, 2023

View reviewed changes

feilongjiang approved these changes Jan 17, 2023

View reviewed changes

RealFYang approved these changes Jan 17, 2023

View reviewed changes

openjdk bot added the ready Pull request is ready to be integrated label Jan 17, 2023

openjdk bot added the sponsor Pull request is ready to be sponsored label Jan 28, 2023

openjdk bot added the integrated Pull request has been integrated label Jan 28, 2023

openjdk bot closed this Jan 28, 2023

openjdk bot removed ready Pull request is ready to be integrated rfr Pull request is ready for review sponsor Pull request is ready to be sponsored labels Jan 28, 2023

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

8299844: RISC-V: Implement _onSpinWait intrinsic #11921

8299844: RISC-V: Implement _onSpinWait intrinsic #11921

yadongw commented Jan 10, 2023 •

edited by openjdk bot

Loading

bridgekeeper bot commented Jan 10, 2023

openjdk bot commented Jan 10, 2023

mlbridge bot commented Jan 11, 2023 •

edited

Loading

feilongjiang left a comment •

edited

Loading

feilongjiang Jan 11, 2023

feilongjiang Jan 11, 2023

luhenry Jan 11, 2023

yadongw Jan 15, 2023

RealFYang left a comment •

edited

Loading

feilongjiang Jan 15, 2023

RealFYang left a comment

openjdk bot commented Jan 17, 2023 •

edited

Loading

yadongw commented Jan 28, 2023

openjdk bot commented Jan 28, 2023

RealFYang commented Jan 28, 2023

openjdk bot commented Jan 28, 2023

openjdk bot commented Jan 28, 2023

		@@ -0,0 +1,91 @@
		/*
		* Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.

8299844: RISC-V: Implement _onSpinWait intrinsic #11921

8299844: RISC-V: Implement _onSpinWait intrinsic #11921

Conversation

yadongw commented Jan 10, 2023 • edited by openjdk bot Loading

Progress

Issue

Reviewers

Reviewing

bridgekeeper bot commented Jan 10, 2023

openjdk bot commented Jan 10, 2023

mlbridge bot commented Jan 11, 2023 • edited Loading

Webrevs

feilongjiang left a comment • edited Loading

Choose a reason for hiding this comment

feilongjiang Jan 11, 2023

Choose a reason for hiding this comment

feilongjiang Jan 11, 2023

Choose a reason for hiding this comment

luhenry Jan 11, 2023

Choose a reason for hiding this comment

yadongw Jan 15, 2023

Choose a reason for hiding this comment

RealFYang left a comment • edited Loading

Choose a reason for hiding this comment

feilongjiang Jan 15, 2023

Choose a reason for hiding this comment

RealFYang left a comment

Choose a reason for hiding this comment

openjdk bot commented Jan 17, 2023 • edited Loading

yadongw commented Jan 28, 2023

openjdk bot commented Jan 28, 2023

RealFYang commented Jan 28, 2023

openjdk bot commented Jan 28, 2023

openjdk bot commented Jan 28, 2023

yadongw commented Jan 10, 2023 •

edited by openjdk bot

Loading

mlbridge bot commented Jan 11, 2023 •

edited

Loading

feilongjiang left a comment •

edited

Loading

RealFYang left a comment •

edited

Loading

openjdk bot commented Jan 17, 2023 •

edited

Loading