> 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. > It is considered to file a SCR for this update a `FramePop` events do not > enforce the `interp-only` mode for a target thread anymore which might break > some expectations (the behavior has been changed). > > Testing: > - test `serviceability/jvmti/vthread/ThreadStateTest` was updated to provide > some extra test coverage > - submitted mach5 tiers 1-6
Serguei Spitsyn has updated the pull request incrementally with one additional commit since the last revision: review: fix iteration order in process_vthread_pending_deopts as it uses remove_at(idx) ------------- Changes: - all: https://git.openjdk.org/jdk/pull/28407/files - new: https://git.openjdk.org/jdk/pull/28407/files/5989906c..1224d1e2 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=28407&range=03 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28407&range=02-03 Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/28407.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/28407/head:pull/28407 PR: https://git.openjdk.org/jdk/pull/28407
