Making PrintEscapeAnalysis a diagnostic option on product VM?

[Chris Newland]

Hi Vladimir,

What do you think the next step is?

I'm not a committer but I'd be happy to submit a patch/webrev that outputs
LogCompilation XML for the kind of EA info I think would be useful.

I've just seen Vitaly's post and I agree a tty 1-liner for each
elimination would also be nice.

Thanks,

Chris

On Fri, June 19, 2015 12:03, Vladimir Ivanov wrote:
> Chris,
>
>
> I'd suggest to look into enhancing LogCompilation output instead of
> parsing VM output. It doesn't require any flag changes and fits nicely into
> existing LogCompilation functionality, so we can integrate it into the
> product, relieving you and JITWatch users from building a companion VM.
>
> Best regards,
> Vladimir Ivanov
>
>
> On 6/19/15 1:16 PM, Chris Newland wrote:
>
>> Hi, hope this is the correct list (perhaps serviceability?)
>>
>>
>> I'm experimenting with some HotSpot changes that log escape analysis
>> decisions so that I can visualise eliminated allocations at the source
>> and bytecode levels in JITWatch[1].
>>
>> My plan was to build a companion VM for JITWatch based on the product
>> VM
>> that would allow users to inspect some of the deeper workings such as EA
>>  and DCE that are not present in the LogCompilation output.
>>
>> I mentioned this to some performance guys at Devoxx and they didn't
>> like the custom VM idea and suggested I put in a request to consider
>> making -XX:+PrintEscapeAnalysis available under
>> -XX:+UnlockDiagnosticVMOptions on
>> the product VM (it's currently a notproduct option).
>>
>> If this is something you would consider than could I also request
>> consideration of -XX:+PrintEliminateAllocations.
>>
>> All I would need is the class, method, and bci of each NoEscape
>> detected.
>>
>> Kind regards,
>>
>>
>> Chris
>>
>>
>> [1] https://github.com/AdoptOpenJDK/jitwatch
>>
>>
>