RFR: 8337657: AArch64: No need for acquire fence in safepoint poll during JNI calls

[Dmitry Chuyko]

This is a tiny change to improve JNI calls performance on AArch64.  In SharedRuntime::generate_native_wrapper() and TemplateInterpreterGenerator::generate_native_entry()  safepoint_poll is made with acquire=true. It comes from the aarch64 implementation of Thread-local handshakes [0], [1]. Presently, it is no longer required [2].

Turning LDAR into regular load has significant performance effect. For instance, NativeCall benchmarks [3] by @simonis on Graviton 2 show following improvements:

-XX:-UseSystemMemoryBarrier (current default)


NativeCall.callingEmptyNative				8.04%
NativeCall.callingJniCriticalArray			1.01%
NativeCall.callingJniCriticalEmpty			6.73%
NativeCall.callingStaticEmpty				10.47%
NativeCall.methodCallingNativeWithArgs			10.73%
NativeCall.methodCallingNativeWithManyArgs		9.41%
NativeCall.staticMethodCallingStaticNativeIntStub	3.68%
NativeCall.staticMethodCallingStaticNativeNoTiered	9.86%
NativeCall.staticMethodCallingStaticNativeWithManyArgs	4.81%


-XX:+UseSystemMemoryBarrier


NativeCall.callingEmptyNative				33.70%
NativeCall.callingJniCriticalArray			3.64%
NativeCall.callingJniCriticalEmpty			34.15%
NativeCall.callingStaticArray				3.02%
NativeCall.callingStaticEmpty				34.25%
NativeCall.methodCallingNativeWithArgs			35.98%
NativeCall.methodCallingNativeWithManyArgs		34.42%
NativeCall.staticMethodCallingStaticNativeIntStub	15.66%
NativeCall.staticMethodCallingStaticNativeNoTiered	35.27%
NativeCall.staticMethodCallingStaticNativeWithManyArgs	32.99%


Similar improvements are observed on different CPUs.

It is especially interesting that -XX:+UseSystemMemoryBarrier variant began to show improvements in cases where there was parity.

Testing: tier1-3 on linux-aarch64.

[0] https://bugs.openjdk.org/browse/JDK-8189596
[1] https://mail.openjdk.org/pipermail/hotspot-dev/2017-November/029264.html
[2] https://mail.openjdk.org/pipermail/hotspot-compiler-dev/2024-July/078715.html
[3] https://github.com/simonis/Java2Native/tree/main/examples/jmh/java2native

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Commit messages:
 - Copyright year
 - Safepoint poll with acquire=false in JNI entry/wrapper

Changes: https://git.openjdk.org/jdk/pull/20420/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20420&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8337657
  Stats: 20 lines in 2 files changed: 0 ins; 15 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/20420.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20420/head:pull/20420

PR: https://git.openjdk.org/jdk/pull/20420