Re: "ps -o %mem" and free memory in Linux

[Klaus Singvogel <deb-user-ml@singvogel.net>]

Victor Sudakov wrote:
> > Perhaps because the php-fpm workers were forked from the same parent
> > and so a lot of theie 'physical' RAM is actually the same RAM as each
> > other, because it's not been modified?
> 
> I see your point, but ps(1) talks about real physical RAM:
> 
> %mem        %MEM      ratio of the process's resident set size  to the physical memory on the machine, expressed as a percentage.  (alias pmem).
> 
> If those php-fpm workers share a lot of virtual (?) memory between one
> another, shouldn't `ps` show it as such?

You sum up this:

< php-fpm individual 1><----   php-fpm   ----   shared  ---->
< php-fpm individual 2><----   php-fpm   ----   shared  ---->
...
< php-fpm individual n><----   php-fpm   ----   shared  ---->

You summed up with awk: indivual[1..n] + n * shared

But the real memory sum is:  indivual[1..n] + 1 * shared

Do you see the difference?
 
Regards,
	Klaus.
-- 
Klaus Singvogel
GnuPG-Key-ID: 1024R/5068792D  1994-06-27