Negative durations?

Y Srinivas Ramakrishna Y.S.Ramakrishna at Sun.COM
Tue Apr 15 22:26:34 UTC 2008

> "Error occurred during initialization of VM Could not reserve enough 
> space for object heap" - on a 4 GB RAM 32 bit Windows box running a 32 
> bit VM with all -Xmx over 768m, I see the previous message. The 

On a Solaris box I might have asked you to truss the run and see
the mmap fail and look at the error code (perhaps we should
expose that error code back to the user above). I am guessing Windows
may have similar functionality (or others on this list might weigh in with
suggestions). I might also have asked for -XX:OnError="pmap %p"
(although i am not sure it works so early in the life of a JVM), if
windows supported something like pmap (it probably does, except
I do not know what it is).

> obvious causes: not enough contiguous memory to accommodate the heap. Fragmentation issues?

Could be. Although you are asking for only (a bit over) 768 M which is very modest
(out of a total virtual address space of 4 GB for the 32 bit VM, OK, may be 2 GB only
on 32-bit windows, but i am guessing you are running 64-bit windows
and so have the entire 4 GB in a 32-bit process.)
Are you starting the JVM through the JNI invocation interface
from within a native process, or is your application pure Java and
you are using the Java command-line launcher?

>  We rebooted - no other stuff running - what 
> other causes are there to produce such a VM start up issue?

The only other reason which you ruled out via a fresh reboot and
checking that nothing else was running and taking up physical
memory or swap was that despite the 4 G RAM, something
else was running and taking up physical memory and swap.

Perhaps someone else on this alias has encountered the
problem, is more familiar w/ windows and may be able to offer suggestions...

-- ramki
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