[SSI-users] Re: CLONE_VM

[Andreas <ro...@co...>]

Ramesh Babu wrote:
> What is CLONE_VM in java process ?
> 
> Jul  9 00:49:31 test1 kernel: Cannot move process 69528 - java has CLONE_VM
> Jul  9 00:49:31 test1 kernel: Cannot move process 69526 - java has CLONE_VM

Hello

CLONE_VM is a bit in the process mask that indicates that the process 
has more than one thread. In the current implementation of the 
posix-Threads each thread is a process with that bit set. Every java 
programm has at least two threads. That is the reason why you cannot 
migrate java processes at the moment. I think there are some people 
working on migratin a "whole" process, but at the moment it doesn't 
work. If you are using a older version of java than 1.3 you can use the 
option -green on order to let java schedule the threads in userspace. 
That isn't as performant as the using of kernel threads, but it works. 
You can migrate that processes.

Andreas

> 
> 
> -------------------------------------------------------
> This SF.Net email sponsored by Black Hat Briefings & Training.
> Attend Black Hat Briefings & Training, Las Vegas July 24-29 - 
> digital self defense, top technical experts, no vendor pitches, 
> unmatched networking opportunities. Visit www.blackhat.com