[jdk17u-dev] Integrated: 8350106: [PPC] Avoid ticks_unknown_not_Java AsyncGetCallTrace() if JavaFrameAnchor::_last_Java_pc not set

[Richard Reingruber]

On Fri, 19 Sep 2025 07:22:50 GMT, Richard Reingruber <rrich at openjdk.org> wrote:

> This pull request contains a backport of commit [d5908231](https://github.com/openjdk/jdk21u-dev/commit/d5908231ebc16f443b3fc9b2ebf03cc4deb67373) from the [openjdk/jdk21u-dev](https://git.openjdk.org/jdk21u-dev) repository.
> 
> There are a few trivial adaptations
> * of copyright headers
> * of the hunk that includes os.inline.hpp because of a diff in the context
> * and because `frame::abi_minframe` was renamed `frame::common_abi` in higher releases
> 
> In addition to these there's a non-trivial adaptation. In jdk17, we cannot use the frame constructor that takes a `pc` as 2nd argument because it requires it not to be `nullptr`. The appropriate [frame constructor to use](https://github.com/openjdk/jdk17u-dev/blob/dca33960959f71ef646d346e328acd27196f5bef/src/hotspot/cpu/ppc/frame_ppc.inline.hpp#L61) is the one that takes `sp` as single argument. It reads the pc from the frames `lr` slot just as [`frame::setup()`](https://github.com/openjdk/jdk21u-dev/blob/43c84df4a3d73ca3b0aeddc738d2e2f0e9f5145a/src/hotspot/cpu/ppc/frame_ppc.inline.hpp#L40) in jdk21.
> 
> This pr depends on https://github.com/openjdk/jdk17u-dev/pull/3949.
> 
> Risk is low because the patch is small and ppc only and the changed method `JavaThread::pd_get_top_frame_for_profiling()` is only used when profiling with jfr or async-profiler.
> 
> The backport passed our CI testing: JTReg tests: tier1-4 of hotspot and jdk. All of Langtools and jaxp. JCK, SPECjvm2008, SPECjbb2015, Renaissance Suite, and SAP specific tests.
> Testing was done with fastdebug builds on the main platforms and also on Linux/PPC64le.

This pull request has now been integrated.

Changeset: c363d3f1
Author:    Richard Reingruber <rrich at openjdk.org>
URL:       https://git.openjdk.org/jdk17u-dev/commit/c363d3f14fda2945021ea374383a660964b2b1c4
Stats:     31 lines in 2 files changed: 21 ins; 0 del; 10 mod

8350106: [PPC] Avoid ticks_unknown_not_Java AsyncGetCallTrace() if JavaFrameAnchor::_last_Java_pc not set

Reviewed-by: mdoerr
Backport-of: d5908231ebc16f443b3fc9b2ebf03cc4deb67373

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PR: https://git.openjdk.org/jdk17u-dev/pull/3957