May 2022 - leyden-dev

Question about Project Leyden: why choose "static run-time images"?
by Glavo 23 May '22

23 May '22

Hello, everyone. I'm excited to see OpenJDK's quest to improve startup speed, but I have a confusion about Project Leyden. As far as I know, there are currently two efforts in the Java community to improve startup speed: * OpenJ9[1], Zing JVM[2] and Dragonwell[3] reduces JIT warm-up time by caching profiling data or JIT results. This approach greatly improves startup speed with little sacrifice in functionality and flexibility. * GraalVM native-image introduces the concept of "closed-world assumption", at the expense of flexibility and partial functionality, statically compiles Java code, reduces startup time and reduces size. Relatively speaking, it is more expensive, and we need to limit ourselves to use it better. When I got to know Project Leyden, it seems to me that its purpose and cost are very much the same as GraalVM native-image. So, why did Project Leyden choose this approach? Why not opt for a more general way like OpenJ9? What decisive advantage does it have over GraalVM native-image that make us need to start over? Thanks [1]: https://docs.azul.com/prime/Use-ReadyNow.html [2]: https://www.eclipse.org/openj9/docs/shrc/#aot-code-and-jit-data [3]: https://github.com/alibaba/dragonwell8/wiki/Alibaba-Dragonwell8-User-Guide#…

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Re: Project Leyden: Beginnings
by Mat Carter 20 May '22

20 May '22

Hi Mark This is great news! We look forward to the discussions and collaborations ahead as this is a major focus area for us and our 1st and 3rd party customers The Microsoft Java engineering group have started looking at the tooling (performance counters and JFR events) that is currently available for developers to understand the impact of their decisions on start-up/warmup (reaching steady-state). We'll surface our initial thoughts and questions about the current state of profiling in the serviceability-dev mailing list. Cheers Mat Sent from Outlook

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Welcome to Project Leyden!
by mark.reinhold＠oracle.com 20 May '22

20 May '22

I’ve published an initial Project page, here: https://openjdk.java.net/projects/leyden/ At the moment Leyden has no repositories, since I expect that at the start we’ll focus more upon concepts than code. We’ll create repositories for documents and code as we need them, and assign roles at that time. - Mark

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