memory usage per process

Sierp

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Feb 11, 2009, 3:27:48 PM2/11/09

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Hello,

I'm thinking about some very simple thing - I was assuming it would be
simple. But it's not that simple.
I'm talking about memory usage, real memory usage for PID and for all
machines PIDs.

Let's say I'm looking at nmon output, and see something like this:

Physical PageSpace
MB Used 15156 2256
MB Free 1740 3887
Total(MB) 16896 6144

Is there any command I could use to check, what exactly is consuming
this 17412MB of RAM?
I know, that some part of memory is used for filesystemcache - in this
case, 10%.
I was thinking about svmon -Pu and taking "Inuse" field, for example I have

svmon -Pu

Pid Command Inuse Pin Pgsp Virtual .....
11111 oracle 755797 65584 303066 746923

but when I add all Inuse/4/1024=something in MB, I recive something more
than 22GB. As I assumed from manual for svmon, this might be becouse of
shared memory between processes, which is every time counted separatly.

In the other hand, when I try to do something like this:

for PID in `ps -ef | awk '{ print $2}'`; do
ps v $PID | grep -v COMMAND | awk '{ print $7}';
done

which means I have all RSS outputs for all PIDs on this machine - and
when I sum all this RSS outputs - I receive value of 4835808, which
means about 4722MB used. About 1700MB is used for filesystem cache.
So this is all I know - I know what is happening with 6,5GB of my RAM,
but what about 10GB of it?
What is utilizing it?

I would be gratefull for good answer, I was googling for it and to be
honest, I couldn't find the answer except what I wrote above.

regards,

Sierp

Andreas Schulze

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Feb 11, 2009, 5:14:06 PM2/11/09

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On 11 Feb., 21:27, Sierp <si...@nolspamatsierp.net> wrote:
>[...] I'm looking at nmon output, and see something like this:

>
> Physical PageSpace
> MB Used 15156 2256
> MB Free 1740 3887
> Total(MB) 16896 6144
>
> Is there any command I could use to check, what exactly is consuming
> this 17412MB of RAM?
> I know, that some part of memory is used for filesystemcache - in this
> case, 10%.

> I was thinking about svmon -Pu and taking "Inuse" field,[...]

You are on the right track by using svmon to identify memory usage.
I'd like to suggest to you that you use the system wide view with
svmon -S instead of the process view with svmon -P. With the system
wiede view every memory segment will show up once and you can also see
memory segments that don't belong to a process.
If you want to know which process uses a certain memory segment use
svmon -P <PID> -l and/or svmon -Pns. Look out for same virtual segment
IDs vsid and shmat/mmap description.
A good starting point for reading IMHO would be the AIX documentation
at the Information Center:
http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.prftungd/doc/prftungd/mem_usage.htm

Henry

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Feb 11, 2009, 5:16:59 PM2/11/09

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I'll be interested because I too have done a lot of work with svmon,
ps (and awk).

I wrote this to translate the svmon -P output to MB and have tried all
sorts with running totals of all procs

cat /opt/local/bin/svmon-P.awk
#!/usr/bin/awk
BEGIN{ printf("%-10s%20s%10s%10s%10s%10s\n",
"Pid","Command","Inuse","Pin","Pgsp","Virtual")}
{
if ( /Pid Command/ )
{
#print
getline
printf("%-10s%20s%10.0f%10.0f%10.0f%10.0f\n", $1, $2, ($3*4/1024),
($4*4/1024), ($5*4/1024), ($6*4/1024))
sum_Inuse+=($3*4/1024)
sum_Pin+=($4*4/1024)
sum_Pgsp+=($5*4/1024)
sum_Virtual+=($6*4/1024)
}
}
END{
printf("%-30s%10.0f%10.0f%10.0f%10.0f\n", "Totals in MB", sum_Inuse,
sum_Pin, sum_Pgsp, sum_Virtual)

so I run this to see if DB2 can be calculated - I don't believe its
correct

#!/bin/ksh
# $Id$

PATH=/usr/bin

function svmon_pid {
# check svmon memory mapping

# see if there's any DB2 processes running
# the ps "comm" and "args" produce different output for the "db2sysc"
command
list_of_db2_pids=$( ps -e -o user,pid,ppid,etime,time,pcpu,args | awk
'$7 ~ "db2sysc|db2agent|db2ckpwd|db2fmp|db2acd" && $5 !=
"00:00:00" {print $2}')
if [[ -n $list_of_db2_pids ]] ; then

# need root for svmon
if [[ $(whoami) != "root" ]]; then
print have to be root user, exiting
exit
fi

echo "svmon stats"
for db2_pid in $list_of_db2_pids ; do
# some output modifications
svmon -P $db2_pid | awk -f /opt/local/bin/svmon-P.awk
done | awk '{print}/Totals in MB/ {sum_Totals+=$4;+
+num_db2_hits}END {print "Totals of all DB2 " sum_Totals " MB - ",
num_db2_hits " PIDS\n"}'
else
echo no DB2 running
exit 0
fi
}

function db2_by_user {
# look through process table for DB2
echo "only show processes using TIME and CPU"
ps -e -o user,pid,ppid,etime,time,pcpu,args| awk '
BEGIN { printf("\n%-10s%-10s%-10s%-15s%-15s%-10s\n", "UID", "PID",
"PPID", "ETIME", "TIME", "CPU%") }
$7 ~ "db2sysc|db2agent|db2ckpwd|db2fmp|db2acd" && $5 != "00:00:00" &&
$6 != "0.0" {
UID=$1
PID=$2
PPID=$3
ETIME=$4
TIME=$5
PCPU=$6
printf("%-10s%-10s%-10s%-15s%-15s%-10s\n" , UID, PID , PPID, ETIME,
TIME, PCPU)
}'

}
# entry point
svmon_pid
db2_by_user

and running it

sudo show_db2_size.sh
svmon stats