UNIX for Advanced & Expert Users

Hello All,

A few questions on same topic.

The memory resident info obtained either from ps (rss) or 'top' (RES) adds upto what is more than actual RAM.
I believe this is due to shared memory mapping of the processes.

So what is the best method to identify the actual ( can I call it as effective ) memory usage/consumption by the processes ?

The 'pmap -x pid' gives information under tabs of Kbytes / Resident / Shared and Private.

Is an arithmetic exercise on these fields give the correct information ?


( Pls look at this info

#ps -e -o pid,vsz,rss grep 21941 gives an output like,

PID VSZ RSS
21941 136168 116408

and the #pmap -x 21941 give the summary as ,

(Kb) (Resident) (Shared) (Private )
total Kb 135424 122320 16736 105584

Any clue why the memory info is different... Which one is *more* correct . ? )

Appreciate your reply. This will clear a lot of confusion on memory usage...


Thanks in advance...

I am sorry, I missed out these information.

Operating system : Solaris 2.6
Pagesize : 8192
RAM : 512 MB

Thanks for the info.
I'm going to run a few test...

When you posted this question, I tried the commands on a sample process on a 2.6 machine and both commands agreed. So I just moved on since I didn't have anything useful to say.

But I just downloaded memtool and the docs say:
I found the instructions to obtain memtool here. Click on "cool tools"; then "memtool". Also on that page, click on "pmap -x", where you will find: So you may be right about pmap.

Hi,

Thanks a lot.. That was a great help...