On Mon, 28 Oct 2024 18:56:25 GMT, Patricio Chilano Mateo <pchilanom...@openjdk.org> wrote:
>> Could the problem be solved with a resume adapter instead, like the >> interpreter uses? > > The issue with the c2 runtime stub on aarch64 (and riscv) is that > cb->frame_size() doesn't match the size of the physical frame, it's short by > 2 words. I explained the reason for that in the comment above. So for a > regular return we don't care about last_Java_sp, rsp will point to the same > place as before the call when we return. But when resuming for the preemption > case, the rsp will be two words short, since when we freezed the runtime stub > we freeze 2 words less (and we have to do that to be able to correctly get > the sender when we walk it). > One way to get rid of this would be to have c2 just set last_Java_pc too > along with last_Java_sp, so we don't need to push lr to be able to do > last_Java_sp[-1] to make the frame walkable. I guess this was a micro > optimization. > Could the problem be solved with a resume adapter instead, like the > interpreter uses? > It will just move the task of adjusting the size of the frame somewhere else. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/21565#discussion_r1819594475
