RFR: 8203832: JWarmup precompile java hot methods at application startup

[David Holmes]

Hi Yumin,

On 15/03/2019 8:57 am, yumin qi wrote:
> Please review the patch for implementing JEP 8203832:

It seems a bit premature for a RFR at this point given the JEP is still 
a draft. Perhaps a RFC is more appropriate?

You need to create an Enhancement issue in JBS, linked to the JEP, to be 
used to push any changes once the JEP has been targeted, then issue your 
RFC/RFR under that bug id.

Thanks,
David
-----

> Bug: https://bugs.openjdk.java.net/browse/JDK-8203832
> Webrev: http://cr.openjdk.java.net/~minqi/8203832/webrev-01/
> 
> Summary: This patch implements the first version of JIT warmup to
> solve the java application peak time CPU contest between JIT compiler
> threads and regula
> r application java threads. The CPU contest is avoided by pre-run to
> collect comilation data and precompile the hot java methods during
> application startu
> p based on the pre-run collected data.
> 
> The main flags (-XX:) used to control are:
> CompilationWarmUpRecording: used for collecting compilation data.
> Result stored in a file set by flag CompilationWarmUpLogfile.
> CompilationWarmUp: use collected data to precompile the methods
> recorded in above file.
> CompilationWarmUpExclude: configure a file which contains the names to
> be excluded for precompile.
> CompilationWarmUpRecordTime: control the warmup recording time.
> CompilationWarmUpDeoptTime: time (from start) to deoptimize precomiled methods.
> 
> In this version, the profiled method data is not used at
> precomilation, it will be addressed in followed bug fix. After the
> first version integrated, will file bug f
> or it. Also, it does not work with CDS since the data added to
> ConstantPool data structure. It also will be addressed in another
> separate bug followed.
> 
> Test: Submitted to submit repo and passed all tests.
> Newly added test suites:  test/hotspot/jtreg/jwarmup include test
> cases for most of the use cases and issues.
> 
> Thanks
> Yumin
>