Deoptimisation and recompilation on HotSpot: uncommon traps and their reason codes, the none / maybe_recompile / reinterpret / make_not_entrant / make_not_compilable actions, jdk.Deoptimization in JFR, -XX:+TraceDeoptimization, the per-method trap limits and recompilation cutoffs, and diagnosing a method that never stabilises. Use when a method repeatedly shows "made not entrant" in the compilation log, when latency spikes correlate with class loading or a deploy, when a burst of "marked for deoptimization" follows a deploy or a plugin load, when a feature flag or APM agent is suspected of invalidating compiled code, when "made not compilable" or a flood of action "none" …
