Re: How to find out how many other processes share VM with $PID?

Fengguang Wu
2007-08-27T12:14:23Z

Hi Denys,

On Mon, Aug 27, 2007 at 12:56:31PM +0100, Denys Vlasenko wrote:
> Hi,
>
> I was a bit frustrated by bad quality of memory usage info
> from top and ps, and decided to write my own utility.
>
> One problem I don't know how to solve is how to avoid counting
> twice (or more) memory used by processes which share VM
> (by use of CLONE_VM flage to sys_clone).
>
> I know how to detect and correctly account for threads
> (processes created with CLONE_THREAD), but how to detect non-threads
> with shared VM?

There is a nice LWN article on this issue:
ELC: How much memory are applications really using?
http://lwn.net/Articles/230975/

Another helpful patch could be:
maps: PSS(proportional set size) accounting in smaps
http://lkml.org/lkml/2007/8/19/23

Fengguang