Diagnosing performance cliffs on JDK7.

[Christian Thalinger]

On Aug 21, 2012, at 2:00 AM, "MacGregor, Duncan (GE Energy)" <duncan.macgregor at ge.com> wrote:

> On 20/08/2012 20:47, "Christian Thalinger"
> <christian.thalinger at oracle.com> wrote:
>> On Aug 20, 2012, at 12:02 PM, "MacGregor, Duncan (GE Energy)"
>> <duncan.macgregor at ge.com> wrote:
>> 
>>> While trying to do some minor performance tuning on how we handle
>>> multiple return results I've finally managed to consistently provoke a
>>> performance cliff in our benchmarks. Logging compilation I see that the
>>> method in question is compiled a couple of times and then produces a
>>> 
>>> COMPILE SKIPPED: out of nodes before macro expansion (not retry able)
>> 
>> What JDK version are you seeing this problem with?
> 
> JDK 1.7.0 update 4, hotspot 23.0.b21

I see.  Honestly I never saw this before with JSR 292 code but I have an idea why this is happening.  It is a performance cliff but a different one than the one we were always talking about.  This might also hit us in the new implementation.  At least now until we revisited our inlining.

Could you try to run this with the latest JDK 8 b52:

http://jdk8.java.net/download.html

That is the first JDK 8 build that contains our new JSR 292 implementation.

-- Chris

> 
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