RFR 8221623 : Add StackWalker micro benchmarks to jdk repo

[Brent Christian]

Hi, Mandy

Yes, that 'make' job would take ~7 hours on my machine.
I believe this is typical for running micros using 'make'.  AFAICT, the 
jmh defaults are used, so it forks (running all the warmups + 
iterations) 5 times.  Trying another (>100 loc) benchmark  at random, 
the java.lang.ArrayCopy one would take 25 hours.

There might be a way to pass jmh args (e.g. '-f 1') via 'make test 
TEST=...', though I really only ever run benchmarks using 'java -jar 
path/to/benchmark.jar'.

It may be worth looking into updating the make target to setup more 
practical JMH runtimes by default.  But I don't think this an issue 
particular the new benchmarks.

Thanks,
-Brent
On 9/18/19 7:33 PM, Mandy Chung wrote:
> Hi Brent,
> 
> $ make test TEST="micro:java.lang.StackWalkBench"
> 
> It took very long that I killed the job.  Does this happen to you?
> 
> Mandy
> 
> On 9/13/19 3:07 PM, Brent Christian wrote:
>> Hi,
>>
>> Please review these StackWalker and Throwable benchmarks for addition 
>> into the JDK microbenchmarks.
>>
>> Bug:
>> https://bugs.openjdk.java.net/browse/JDK-8221623
>> Webrev:
>> http://cr.openjdk.java.net/~bchristi/8221623/webrev07/
>>
>> The StackWalker benchmarks use StackWalker's forEach(), walk(), and 
>> Options to measure retrieval of various types of information from the 
>> call stack.
>>
>> The Throwable benchmarks do corresponding exercises; there are also a 
>> couple of Logging benchmarks.
>>
>> A JMH @Param is used to test a variety of call stack depths.
>>
>>
>> In the future, we might consider a benchmark for 
>> Reflection.getCallerClass().  (It is more involved today to benchmark 
>> that method than at the time these benchmarks were originally written, 
>> so that one's commented out.) See JDK-8230976.
>>
>> Thanks,
>> -Brent
>>
>> 1. https://bugs.openjdk.java.net/browse/JDK-8230976
>