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Re: Strange Performance Tests
On Wed, 2002-07-10 at 21:48, Michael Smith wrote:
> Lars Andersen wrote:
> > On Wed, 2002-07-10 at 21:21, Andrew Pinski wrote:
> >
> >>I think the spikes in both are the gc (garbage collector) running.
> >>The gc for gcj is boehm's which might be slower than the one
> >>used by Sun.
> >>
> >>Thanks,
> >>Andrew Pinski
> >
>
> try increasing the initial heap size.
>
> For gcj,
> export GC_INITIAL_HEAP_SIZE=<size>
>
> For the jdk,
> java -Xmx<size>
>
> If the spikes occur less frequently, but have longer times, that would
> be indicative of the GC.
>
OK, the plot thickens!
I tried with following settings of GC_INITIAL_HEAP_SIZE:
16000000, 32000000 and 128000000
GCJ now runs as fast or faster than SUN jdk1.4 regardless of what
initial heapsize I choose!
Apparently, just setting the initial heap size to something more than
doubles the performance of my app!!!
/Lars Andersen