On Thu, 22 Aug 2024 05:47:23 GMT, Tobias Hartmann <thartm...@openjdk.org> wrote:
>> Greetings, >> >> Please help review this change set that implements C2 intrinsics for >> jdk.internal.vm.Continuation.pin() and jdk.internal.vm.Continuation.unpin(). >> >> This work is a consequence of >> [JDK-8338417](https://bugs.openjdk.org/browse/JDK-8338417), which required >> us to introduce explicit pin constructs for Virtual threads in a relatively >> performance-sensitive path. >> >> Testing: jdk_jfr, loom testing >> >> Comment: I changed the type of the ContinuationEntry::_pin_count field from >> uint to uin32_t to make the size explicit and to access it uniformly from >> the intrinsic code using T_INT. >> >> Thanks >> Markus > > src/hotspot/share/opto/library_call.cpp line 3787: > >> 3785: set_all_memory(input_memory_state); >> 3786: uncommon_trap_exact(Deoptimization::Reason_intrinsic, >> 3787: Deoptimization::Action_reinterpret); > > Why do you use `Action_reinterpret` and not `Action_make_not_entrant` here? > > You may need a check to avoid endless re-compilation of a method that always > hits the trap: > > if (too_many_traps(Deoptimization::Reason_intrinsic)) { > return false; > } > > > See other intrinsics. A pin_count overflow/underflow should be a per-thread condition, not global. If there is nothing in the nmethod to be invalidated, maybe this should be `Action_none`? ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/20664#discussion_r1726482790
