Re: Java processors

From:

Lew <lewbloch@gmail.com>

Newsgroups:

comp.lang.java.programmer

Date:

Fri, 6 Jul 2012 11:31:56 -0700 (PDT)

Message-ID:

<3c14dbeb-bd6a-4b37-998b-5afe1802e6bc@googlegroups.com>

Arne Vajh=F8j wrote:

(or equivalent) is rather aggressive about JIT compiling.

.NET CLR always does it first time I believe.

WRT Java, there are options such as "-XX:CompileThreshold=10000" (default=
for -server).

That means that the HotSpot compiler sees the same code 10000 times
before deciding to compile it.

<http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.ht=
ml>

There's a reason performance white papers for Java discuss
GC and other options. They can influence performance more than
JIT does.

<http://www.oracle.com/technetwork/java/javase/tech/performance-jsp-141338.=
html>

Not that optimization of the JITter is a bad idea.

<http://www.oracle.com/technetwork/java/6-performance-137236.html#2.1.6>

You can see the effect of memory and other non-JIT enhancements on
the performance of Java 6 here:
<http://www.oracle.com/technetwork/java/6-performance-137236.html#2.3>

<http://www.oracle.com/technetwork/java/hotspotfaq-138619.html>

Perhaps the source code will help you understand:
<http://openjdk.java.net/groups/hotspot/>

--
Lew