[ILUG] determining how much memory is shared between multiple processes?

[Paul Jakma]

On Sun, 3 Oct 2004, Justin Mason wrote:

>  t: SHR  --  Shared Mem size (kb)
>    The amount of shared memory used by a task.  It simply reflects
>    memory that could be potentially shared with other processes.
>
> but some investigation seems to indicate that on my 2.6.6 system, 
> that *only* applies to code pages loaded from shared libraries; 
> pages allocated on the heap are never listed in this field, even if 
> they are unmodified and therefore, presumably, shared.

Sounds like top simply uses the VmLib value (and probably + VmExe 
value) from /proc/<pid>/status, used the source? ;)

> Anyone got any good tips for ways to figure this out?

I dont think even the kernel knows ;) - well it used not to. With 
rmap in the kernel, it now probably does, however I dont see any 
obvious place where that information is exposed..

regards,
-- 
Paul Jakma	paul at clubi.ie	paul at jakma.org	Key ID: 64A2FF6A
Fortune:
"An ounce of prevention is worth a pound of purge."