Re: [Cs-studio-users] Filling Memory when observing PVs

[Kasemir, K. <kas...@or...>]

Hi:

I don't understand.
If you set -Xmx256m, that defines the overall memory limit. The JVM could stop because what you want to do is not possible with -Xmx256m. It shouldn't keep growing to the point where the Linux oom-killer becomes active.
There may be some difference between what the JVM considers "256m" and what Linux sees for the overall process, but there's a huge difference between -Xmx256m = 256 MB and total-vm:7278584kB = 7GB. Maybe the -Xmx256m wasn't effective? Where did you specify it?

As for perm gen space, there is a default limit built into the product. It's not unlimited. Perm gen space is as you say for classes, strings, ..,it doesn't tend to grow with runtime except for that Jython problem where each newly executed Jython file uses new perm gen space memory.

Thanks,
Kay

On Jun 25, 2014, at 1:39 PM, mar...@pt... wrote:
Hi, 
> 
> I started the process with -Xmx256m but without any definition for perm size. Does this mean I am allowing 
> (theoretically) infinite perm gen space for the process/vm ? But does this matter since in perm gen there 
> are classes, Strings and other static stuff and the dynamically allocated space for objects etc. ist stored on 
> the heap (which has a limit) ? 
> I will try to repeat the tests with the perm gen size limit and see what happens... 
> Curious what will happen when using Java 8 where the perm gen limit parameter has been removed: http://openjdk.java.net/jeps/122 . 
> 
> P.S. The 45,6% Memory process stopped running because the linux oom-killer process decided to stop it: 
> 
> [So Jun 22 21:09:41 2014] Out of memory: Kill process 21744 (java) score 474 or sacrifice child 
> [So Jun 22 21:09:41 2014] Killed process 21744 (java) total-vm:7278584kB, anon-rss:4446556kB, file-rss:968kB 
> 
> Marcus