Request for reviews (XS): 6873799 and 6873800

Ismael Juma mlists at
Thu Aug 20 02:49:52 PDT 2009


Christian Thalinger <Christian.Thalinger at ...> writes:
> Well, "always" is probably not true.  But nowadays most applications
> rely heavily on memory throughput and it's definitely a win there.

That has also been my experience when benchmarking an internal application.
David Dagastine also wrote:

"64-bit Compressed Oops Performance Optimization: 64-bit now surpasses 32-bit

That's a bit vague, but it was common to see a small performance disadvantage
for the 64-bit JVM versus the 32bit JVM when running some of the well known
benchmarks, so compressed oops seems to be a win there too.

> But sure Vladimir has some numbers when he wakes up.

That would be interesting information.

For what is worth, I think it's great that compressed oops and escape analysis
will be enabled by default in HotSpot 17. Aside from performance improvement,
the former has a significant effect in terms of memory usage (and we know that
JVM needs all the help it can get there). The latter, on the other hand, helps
with the excessive allocation (including boxing) that takes place in certain
cases in Scala (my favoured programming language these days).



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