RFR(XS): JDK-8010941: MinJumpTableSize is set to 18, investigate if that's still optimal

Aleksey Shipilev aleksey.shipilev at oracle.com
Fri Sep 6 05:02:01 PDT 2013


On 09/06/2013 03:54 PM, Niclas Adlertz wrote:
>> It is customary for us (perf guys) to create multiple
>> @GMB methods with different problems sizes, and run them in single JMH
>> session.
> That would have been smarter, yes. I'll do that next time. Thanks.
> And thank you for helping me with JMH. 

Sure, any time.

>> Yes, "10" seems the turn-point for X64; for SPARC, I'd set it to "5".
> Ok, I'll have one value for each platform instead. 
> 
> WEBREV: http://cr.openjdk.java.net/~adlertz/JDK-8010941/webrev02/

Good!

I worry about the 32-bit x86 though. It seems the register pressure with
jump tables is higher? If so, the turn-point for x86 can be even larger.
Can you double-check the 32-bit x86 VM?

-Aleksey.



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