JEP 515: Ahead-of-Time Method Profiling

Summary Improve warmup time by making method-execution profiles from a previous run of an application instantly available, when the HotSpot Java Virtual Machine starts. This will enable the JIT compiler to generate native code immediately upon application startup, rather than having to wait for profiles to be collected. Goals Help applications warm up more quickly by shifting the collection of initial method execution profiles from production runs to training runs, conveying the profiles via the AOT cache. Do not require any change to the code of applications, libraries, or frameworks. Do not introduce any new constraints on application execution. Do not introduce new AOT workflows, but, rather, use the existing AOT cache creation commands. Motivation To truly know what an application does, we must run it. We can draw simple conclusions about an application's behavior by inspecting its source code or its class files, but we will be uncertain about how it interacts with the hig ... Read full article.