Hi Weldon,

I've tried both the patched Mix.java and MegaSpawn.java and they produce similar behavior on my RHEL4/core2duo box.

Both cause a series of OOME events and then hang. I've also run both using the Sun 1.5.0_09 JVM and both run to completion.

So, it seems that MegaSpawn.java faithfully reproduces the bug. Nice work!

Naveen

On Jan 5, 2007, at 3:09 PM, Weldon Washburn wrote:

Rana,

Can you try MegaSpawn.java that I attached to harmony-2803? Its basically a version of stress.Mix with all the non-essential stuff removed. I would like to know if it faithfully reproduces the bug(s) in your environment. It would be great if this is indeed true since we would have a simple test that
always breaks the jvm.  This makes for much easier debug.

I also see what you observe below. I also like the idea of killing the "occupy" thread. It seems there might be some notion of memory quota --
something for which I have been waiting a long time.

From the below, the hang is observed on both winxp and linux. If this is
correct, we can focus on the OS independent code  :)



On 1/5/07, Rana Dasgupta <[EMAIL PROTECTED]> wrote:

HI Weldon,
  On a 2 cpu smp RHEL4 box:
    - on RI the modified test always passes
    - DRLVM always fails with OOME when trying to spawn threads

On a 2 cpu XP box:
- RI kills the "occupy" thread( I thought this is really smart ), but
passes
- DRLVM sometimes passes, sometimes hangs, occassionally reports invalid
memory references, VM launcher errors etc. etc.


Rana

On 1/5/07, Weldon Washburn <[EMAIL PROTECTED]> wrote:
>
> All,
>
> An update. I think I can cause the bug(s) we are discussing in this
email
> chain to surface 100% of the time on 2 cpu rhel4. Hacking stress.Mixsuch > that it only runs the "spawn" method seems to do it. This hack always
> fails on 2 cpu rhel4 and never fails on 1 cpu winxp.  It would be
> interesting to try on 1 cpu rhel4 and 2 cpu winxp. If anyone has this > combination, please try it. This would tell us if the bug is sensitive
to
> OS.
>
> When I run the below patch on RI, it completes successfully every time. > Curiously it looks like the RI kills the "occupy" thread. It prints on
> the
> console output, "occupy terminated by java.lang.OutOfMemoryError..
.".  But
> I
> don't see occupy terminate when running drlvm.  I will run more
> tests.  This
> may actually be compounding the problems we are seeing.
>
> Naveen, Rana,
> Can you try the below patch on your hardware to see if you can reproduce > what I describe above? Does the output look the same as Harmony-2803?
>
>
> Below is an svn diff that makes the hard failure happen on 2 cpu rhel4:
>
> Index: Mix.java
> ===================================================================
> --- Mix.java    (revision 491852)
> +++ Mix.java    (working copy)
> @@ -93,6 +93,8 @@
>
>     static Random random = new Random(0);
>     static String selectThreadType(int i) {
> +               return "spawn";
> +               /*
>         switch (i % 9) {
>             case 0: return "uncontended";
>             case 1: return "contended";
> @@ -105,6 +107,7 @@
>             case 8: return "exceptions";
>         }
>         return "nothing";
> +               */
>     }
>
>     static int thread_number = 60;
>
>
>
> On 1/4/07, Naveen Neelakantam <[EMAIL PROTECTED]> wrote:
> >
> >
> > On Jan 4, 2007, at 4:28 PM, Weldon Washburn wrote:
> >
> > > I see it hang consistently when running automated mode (build
> > > test).  I have
> > > seen it hang once when running manually from a linux terminal
> > > window.  It
> > > actually printed out "PASSED" then hung. This leads me to suspect
> > > there
> > > might be problems with how System.out.flush() is working when there
> > > are
> > > multiple threads running on SMP. Are you running on an SMP box?
> > > Can you
> > > give me the exact command line you are using? I would like to try
> > > it on my
> > > box.
> >
> > Ok, cool. I was seeing the exact same behavior (i.e. the test prints
> > PASSED and then hangs).  So it sounds like you are on the right
> > track, to me anyway.
> >
> > But to answer your questions: I am running RHEL4 update 4 on a core2 > > duo. The command line I am using is "java -cp . stress.Mix" (with my
> > path and JAVA_HOME set appropriately).
> >
> > Naveen
> >
>
>
>
> --
> Weldon Washburn
> Intel Enterprise Solutions Software Division
>
>




--
Weldon Washburn
Intel Enterprise Solutions Software Division

Reply via email to