ReentrantLock performance regression between JDK5 and 6/7?
fweimer at bfk.de
Fri Aug 12 00:57:50 PDT 2011
* Tom Rodriguez:
> I believe this was caused by the switch to using lock addl[esp], 0
> instead of mfence for volatile membars, 6822204. My review request
> for that said that at the time I didn't measure any performance change
> for Intel, http://cr.openjdk.java.net/~never/6822204. On your
> microbenchmark I can measure the difference though so I'm going to
> remeasure derby which previously showed the big difference. We may
> want to make the lock addl be AMD specific.
Couldn't the relative speed of the two instructions also depend on the
type of benchmark?
Florian Weimer <fweimer at bfk.de>
BFK edv-consulting GmbH http://www.bfk.de/
Kriegsstraße 100 tel: +49-721-96201-1
D-76133 Karlsruhe fax: +49-721-96201-99
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