I apologize for not following up on this sooner. Andrei, spot on with the deoptimizations on JDWP agent. This JDWP deopt insanity is what I am observing in my development environment.
Martijn, as I was chasing JDWP deopts I refactored the code a little bit and since then not seeing any deoptimization issues on production hardware when running performance tests. Now I am seeing performance improvements consistent across all of the performance tests. Looks very good. Before some performance tests performed worse with the optimized code which confused me quite a lot. A bit unsure which code change fixed it. But don't feel like spending more time on this for now as the problem is fixed. This has been an interesting learning experience. Thank you Alen V V sob., 24. dec. 2022 ob 07:28 je oseba Martijn Verburg < [email protected]> napisala: > Just saw this super late - sorry! Which version of the JVM were you using > and do you have a small reproducer? > > On Tue, 20 Dec 2022 at 07:56, Alen Vrečko <[email protected]> wrote: > >> Hello everyone. >> >> I am looking at a case where around 30% of CPU time is spent by the JVM >> in deoptimizations (done the profile with async-profiler). >> >> I can locally reproduce the case. The log just explodes with >> deoptimization messages. A few methods get deoptimized all the time. I >> didn't stopwatch the deoptimization log count but it is in the order >> 100s-1000s of them in a span of few seconds - consistently. >> >> Did JIT eliminate a branch by mistake? Then it figured it should be there? >> >> If there is a high number of method calls, could it trigger some dead >> code elimination prematurely? >> >> Any ideas? >> >> Thank you >> Alen >> >> -- >> You received this message because you are subscribed to the Google Groups >> "mechanical-sympathy" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web, visit >> https://groups.google.com/d/msgid/mechanical-sympathy/CACOdjgQaGqHN_uPU_EjowQ5_7jBfKE0a5kLeWSxScE9OTBdhRg%40mail.gmail.com >> <https://groups.google.com/d/msgid/mechanical-sympathy/CACOdjgQaGqHN_uPU_EjowQ5_7jBfKE0a5kLeWSxScE9OTBdhRg%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > -- > Cheers, Martijn (Sent from Gmail Mobile) > > -- > You received this message because you are subscribed to the Google Groups > "mechanical-sympathy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/mechanical-sympathy/CAP7YuASP_f264NwsrCc3WLNGOhCg3Kn6J2hH-8d_bM9FSamUng%40mail.gmail.com > <https://groups.google.com/d/msgid/mechanical-sympathy/CAP7YuASP_f264NwsrCc3WLNGOhCg3Kn6J2hH-8d_bM9FSamUng%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "mechanical-sympathy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/mechanical-sympathy/CACOdjgRWG-yna1axA1vR6_-ps-TJuddWP8Lz7EPwsqZqx028Jg%40mail.gmail.com.
