Hi Tedapt,
Looks like a kernel bug to me; most likely something with the archaic
version of linux that TS supplies with their 7xxx series of boards. Can
you record what is coming off of the console when this happens?
Your best bet is to work around the problem by rewriting (or just
recompiling) your application in C.
Your memory pattern demonstrates the typical java sawtooth graph -
after a collection memory is restored and the system continues
(presumably after an enormous pause). I would strongly recommend
rewriting (or just recompiling) your code in C and thinking quite hard
about the memory management of it. Remember you're running Java on an
embedded platform; thus the interpreter wastes memory, and power; and
with Java's garbage collection you'll never get real-time guarantees.
I do a lot of work at a Java house that has about 1000 cores dedicated
for running servers. I (we) consistently watch memory management
problems bring down our projects after observing hours of sawtooth
graphs, like yours.
-bms
tedapt wrote:
>
>
> I have posted the following Memory graphs
> <http://groups.yahoo.com/group/ts-7000/photos/album/917845361/pic/list?mode=tn&order=ordinal&start=1&dir=asc>
>
> which illustrate the problematic memory pattern and also the pattern
> observed when the application runs without any problems.
>
> --- In "tedapt" <> wrote:
> >
> > Hi all -
> >
> > I have a data logging JamVM application on ts-7260 boards running
> Debian from an SD card. In some of my applications configurations, I
> find that the Buffers value obtained from `free` rises, then falls to
> zero over the course of about six hours. Once Buffers hits zero, the
> boards become unreachable, and all application processes appear to
> hang until a power cycle.
> >
> > In other configurations, the Buffers value rises and stays above the
> Free value, following a sawtooth pattern. On these boards, all remains
> OK for long periods. Occasionally I've seen these boards suddently
> exhibit a similar memory pattern, with Buffers suddenly declining
> until reaching zero, and again these boards become unreachable.
> >
> > I'm at a loss to understand what is happening. Have experimented
> with swap files, new versions of JamVM, code modifications and some
> sysctl settings, examined netstat, lsof output, all without any
> improvements.
> >
> > Has anyone every seen anything like this, or have any suggestions
> for solving this problem?
> >
> > Thanks!
> >
>
>
>
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