On Fri, 22 May 2026 09:47:16 GMT, Serguei Spitsyn <[email protected]> wrote:
>> This change fixes a long standing performance issue related to the debugger >> single stepping that is using JVMTI `FramePop` events as a part of step over >> handling. The performance issue is that the target thread continues its >> execution in very slow `interp-only` mode in a context of frame marked for >> `FramePop` notification with the JVMTI `NotifyFramePop`. It includes other >> method calls recursively upon a return from the frame. >> >> This fix is to avoid enforcing the `interp-only` execution mode for threads >> when `FramePop` events are enabled with the JVMTI >> `SetEventNotificationMode()`. Instead, the target frame has been deoptimized >> and kept interpreted by disabling `OSR` optimization by the function >> `InterpreterRuntime::frequency_counter_overflow_inner()`. (Big thanks to >> @fisk for this suggestion!) Additionally, some tweaks are applied in several >> places where the `java_thread->is_interp_only_mode()` is checked. >> The other details will be provided in the first PR request comment. >> >> Testing: >> - test `serviceability/jvmti/vthread/ThreadStateTest` was updated to >> provide some extra test coverage >> - submitted mach5 tiers 1-6 >> >> - [x] I confirm that I make this contribution in accordance with the >> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). > > Serguei Spitsyn has updated the pull request incrementally with one > additional commit since the last revision: > > review: 1. Add asserts, rem comment 2. Remove can_generate_frame_pop_events > from can_generate_interpreter_events The JVMTI source code and test changes look good. There are few small questions/checks. I haven't reviewed changes in frame.cpp. src/hotspot/share/interpreter/interpreterRuntime.cpp line 1077: > 1075: assert(last_frame.is_interpreted_frame(), "must come from > interpreter"); > 1076: > 1077: if (JvmtiExport::can_post_frame_pop() && > JvmtiExport::has_frame_pop_for_top_frame(current)) { Shouldn't be this guarded by 'INCLUDE_JVMTI' or something similar? src/hotspot/share/prims/jvmtiImpl.hpp line 41: > 39: // Forward Declaration > 40: > 41: class JvmtiEnv; Just to double check, if it still needed? ------------- Marked as reviewed by lmesnik (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/28407#pullrequestreview-4365818495 PR Review Comment: https://git.openjdk.org/jdk/pull/28407#discussion_r3305483151 PR Review Comment: https://git.openjdk.org/jdk/pull/28407#discussion_r3305680319
