the memory usage of hotspot vm itself

[Srinivas Ramakrishna]

Use pmap -s -x to look at what's in the virtual address space of yr process
and what portion thereof is resident in physical memory.
Make sure (in your sizing estimate) to leave enough RAM for
(1) other active processes in the system besides ye JVM
(2) your JVM's heap, perm gen, code cache
(3) your JVM's thtread stacks
(4) direct buffer memory and any other native memory used by yr process

-- ramki

On Thu, Mar 1, 2012 at 3:13 AM, Li Li <fancyerii at gmail.com> wrote:

>     I have an application running in a machine with 6 GB memory. And the
> java program is allocated to use 4000M heap by -Xmx4000m and -Xms4000m. But
> we found it use swap memory and system get slower.
> When swapping, the total memory used by the java process is 4.6GB(use top
> res 4.6G and virt 5.1G)
>    I know Direct Buffer used by NIO, PermGen and stack is not limited by
> Xmx. we limit stack 256k and 400 threads in peak. so it will use 80MB
> memory and MaxPermSize is 256MB. MaxDirectMemorySize is default. I think is
> 64MB
> all sumed up is about 3400MB. so JVM itself will need more than 200MB.
>    any one tell me why JVM need more than 200MB memory?(I don't mean jvm
> should not use that much memory). how could I estimate the memory usage of
> JVM itself? thanks.
>
>
> _______________________________________________
> hotspot-gc-use mailing list
> hotspot-gc-use at openjdk.java.net
> http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.openjdk.java.net/pipermail/hotspot-gc-use/attachments/20120301/d9fcddcd/attachment.html