Oracle Database Discussions

Trying to determine how much memory, if any, is allocated at OS level for oracle processes outside PGA/SGA and shared libraries
So that when estimating memory sie for a Linux server processes*x is taken into account

i.e: RAM *.8 >= SGA + PGA + processes*X

X is the number I'm trying to estimate...

So: 11g Database, Using Huge Pages ASMM - RHEL 6

I connect an session to database and get:

oracle level:

SID  Oracle User  O/S User Session Program     Machine PGA Memory (Kb) PGA Memory Max (Mb) UGA Memory (Kb) UGA Memory MAX (Mb)
--- ------------ --------- ------------------ -------- --------------- ------------------- --------------- -------------------
204         USRX      USRX sqlplusw.exe       WIN0010            1977                   2             370                   1

so right at connect time, it's some 2Mb PGA

And OS side:

cat /proc/17880/status

VmPeak:  1288268 kB
VmSize:   237644 kB
VmLck:         0 kB
VmHWM:     23856 kB
VmRSS:     23856 kB
VmData:     3816 kB
VmStk:       144 kB
VmExe:    183512 kB
VmLib:     15024 kB
VmPTE:       396 kB
VmSwap:        0 kB

and about same numbers if I use pmap -x

Then I execute some PL to allocate some 3GB PGA

declare
 type myarray is table of varchar2(255) index by binary_integer;
 x  myarray;
 begin
 for i in 1 .. 10000000 loop x(i) := rpad('x',255,'x'); end loop;
 end;
/

As expected, once PL completes I see:

SID  Oracle User  O/S User Session Program     Machine PGA Memory (Kb) PGA Memory Max (Mb) UGA Memory (Kb) UGA Memory MAX (Mb)
--- ------------ --------- ------------------ -------- --------------- ------------------- --------------- -------------------
164         USRX      USRX sqlplusw.exe       WIN0010            3257                2970             498                   1

So we used some 3Gb, and gave it back to OS upon completion

So far so good... Now Os level

While PL is running (PGA being used) I see:

VmPeak:  4382556 kB
VmSize:  2479964 kB
VmLck:         0 kB
VmHWM:   3069708 kB
VmRSS:   2229752 kB 
VmData:     3816 kB 
VmStk:       160 kB 
VmExe:    183512 kB
VmLib:     15024 kB
VmPTE:      4712 kB
VmSwap:        0 kB
Threads:        1

So VmRSS: 2229752 kB, shows PGA is being accounted as such...
As expected, after PL completes we get:

VmPeak:  4382556 kB
VmSize:   239452 kB
VmLck:         0 kB
VmHWM:   3069708 kB
VmRSS:     32040 kB 
VmData:     3816 kB
VmStk:       160 kB
VmExe:    183512 kB
VmLib:     15024 kB
VmPTE:       452 kB
VmSwap:        0 kB
Threads:        1

So VmRSS noticeably came down

Yet others like VmData, VmStk stayed put

Would it be correct to say that PGA goes in VmRSS and VmData + VmStk (4Mb) is that non shared "extra"os memory each single process would use?

thanks