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From Leo Przybylski <>
Subject RE: Memory issues
Date Thu, 12 Dec 2002 17:51:20 GMT
On Thu, 2002-12-12 at 10:03, Shapira, Yoav wrote:
> Hi,
> What OS (and version) and JDK version you're using?
> It could be that your OptimizeIt version is too old (it's Borland, not
> Inprise, for a while now) to run with the JDK you're using?  I like
> OptimizeIt, been using it since 4.0, and it's a good tool.
The system is Redhat 7.2 with default SMP kernel. I'm using jdk1.3.1_06
(Borland states this should be fine in retrospect to jdk1.4.1). I am
only using the trial version for profiling right now. We are evaluating
and may purchase the full version.

> If you're using linux, the thread memory usage is cumulative not
> separate, despite the display of the "top" command.  So you don't have
> 57*64, but 57 threads sharing 64MB.  This has been discussed on this
> list many times: search the archives for more info on linux memory
> usage.
> >of memory" error. Perhaps that is what I am noticing. I still do not
> >know why I am getting it though.
> Your profiler should tell you where memory is allocated.
> >> Could it be that you simply need more than the default 64MB memory?
> >I don't know. The machine has 1GB of physical and 2GB virtual memory.
> >With the total of java processes at 64MB each and 57 of them running,
> my
> >machine is almost depleated.
> See above regarding interpretation of thread memory usage.
> The heap is shared among all threads in the JVM, so what you specify as
> -Xmx is not per-thread and your machine physical memory will not be
> depleted.

Thank you. I will read up on this. I had no idea. I had been using
vmstat, top, and /proc to get information related to how much memory I
am using. All this time, I did not realize they were inaccurate because
they were indiscriminant of shared memory.

When gtop reported there was 1GB resident for java, it made our system
administrators drop a pantload and they flamed me.

> Yoav Shapira
> Millennium ChemInformatics
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