topic Re: Process Limitations in Operating System - Linux

Process Limitations

TJ_22 — Tue, 19 Jul 2005 06:05:41 GMT

OS: Linux Enterprise 3.0 Update 4

We will be running a new application off of our servers which will spawn multiple child processes from the parent creating some fairly large threads.

I am hoping to find out the following information:

1. How may open files can I have per thread?
2. How much memory is allocated per process (parent + childs)?
3. Any other limitations that I would need to be aware of?

Thanks in advance for your help.

Re: Process Limitations

Gopi Sekar — Tue, 19 Jul 2005 06:19:34 GMT

try 'ulimit -a' which should give most of the details you are looking for.

But for modifying the values you got to be a root user.

Regards,
Gopi

Re: Process Limitations

Stuart Browne — Tue, 19 Jul 2005 06:21:42 GMT

'/proc/sys/fs/file-max' is the maximum number of vavailable file handles. I think it usually defaults to 32k, but I've got mine set to 128k without any issues (and I use 'em). It just uses a bit more memory at the kernel level, no big deal.

The amount of memory per process is limited to the amount of memory on the stack, unless you've used 'ulimit -m ' to set it smaller. See 'man ulimit' for more on that.

Other limitations? It depends on what you're doing I guess. If you're worried, give some more details about what you're doing, and we'll try think of anything else.

If you want to browse around in some of the preset limits in '/proc/sys/*', you might find something else which might affect you. I'd also advise reading through '/usr/share/doc/kernel-doc-*/filesystems/proc.txt' to see what most of those bits and pieces do.

Hope this helps.

Re: Process Limitations

TJ_22 — Tue, 19 Jul 2005 06:21:59 GMT

Thanks!