On Sat, 26 Oct 2024 06:51:08 GMT, Richard Reingruber <rr...@openjdk.org> wrote:
>> src/hotspot/cpu/aarch64/interp_masm_aarch64.cpp line 1555: >> >>> 1553: // Make VM call. In case of preemption set last_pc to the one we >>> want to resume to. >>> 1554: adr(rscratch1, resume_pc); >>> 1555: str(rscratch1, Address(rthread, JavaThread::last_Java_pc_offset())); >> >> Is it really needed to set an alternative last_Java_pc()? I couldn't find >> where it's used in a way that would require a different value. > > Its indeed difficult to see how the value is propagaged. I think it goes like > this: > > - read from the frame anchor and set as pc of `_last_frame`: > https://github.com/pchilano/jdk/blob/66d5385f8a1c84e73cdbf385239089a7a9932a9e/src/hotspot/share/runtime/continuationFreezeThaw.cpp#L517 > - copied to the result of `new_heap_frame`: > https://github.com/pchilano/jdk/blob/66d5385f8a1c84e73cdbf385239089a7a9932a9e/src/hotspot/cpu/aarch64/continuationFreezeThaw_aarch64.inline.hpp#L99 > - Written to the frame here: > https://github.com/pchilano/jdk/blob/66d5385f8a1c84e73cdbf385239089a7a9932a9e/src/hotspot/cpu/aarch64/continuationFreezeThaw_aarch64.inline.hpp#L177 > - Here it's done when freezing fast: > https://github.com/pchilano/jdk/blob/66d5385f8a1c84e73cdbf385239089a7a9932a9e/src/hotspot/share/runtime/continuationFreezeThaw.cpp#L771 Thanks, that's what I was missing. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/21565#discussion_r1819586705
