How can I measure the actual memory usage of an application or process?

Question

This question is covered here in great detail.

How do you measure the memory usage of an application or process in Linux?

From the blog articl

Answer 1

I'm using htop; it's a very good console program similar to Windows Task Manager.

Answer 2

Try the pmap command:

sudo pmap -x <process pid>

Answer 3

Beside the solutions listed in the answers, you can use the Linux command "top". It provides a dynamic real-time view of the running system, and it gives the CPU and memory usage for the whole system, along with for every program, in percentage:

top

to filter by a program PID:

top -p <PID>

To filter by a program name:

top | grep <PROCESS NAME>

"top" provides also some fields such as:

VIRT -- Virtual Image (kb): The total amount of virtual memory used by the task

RES -- Resident size (kb): The non-swapped physical memory a task has used ; RES = CODE + DATA.

DATA -- Data+Stack size (kb): The amount of physical memory devoted to other than executable code, also known as the 'data resident set' size or DRS.

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.

Reference here.

Answer 4

If your code is in C or C++ you might be able to use getrusage() which returns you various statistics about memory and time usage of your process.

Not all platforms support this though and will return 0 values for the memory-use options.

Instead you can look at the virtual file created in /proc/[pid]/statm (where [pid] is replaced by your process id. You can obtain this from getpid()).

This file will look like a text file with 7 integers. You are probably most interested in the first (all memory use) and sixth (data memory use) numbers in this file.

Answer 5

Based on answer to a related question.

You may use SNMP to get the memory and CPU usage of a process in a particular device on the network :)

Requirements:

• the device running the process should have snmp installed and running
• snmp should be configured to accept requests from where you will run the script below (it may be configured in file snmpd.conf)
• you should know the process ID (PID) of the process you want to monitor

Notes:

• HOST-RESOURCES-MIB::hrSWRunPerfCPU is the number of centi-seconds of the total system's CPU resources consumed by this process. Note that on a multi-processor system, this value may increment by more than one centi-second in one centi-second of real (wall clock) time.

• HOST-RESOURCES-MIB::hrSWRunPerfMem is the total amount of real system memory allocated to this process.

**

Process monitoring script:

**

echo "IP: "
read ip
echo "specfiy pid: "
read pid
echo "interval in seconds:"
read interval

while [ 1 ]
do
    date
    snmpget -v2c -c public $ip HOST-RESOURCES-MIB::hrSWRunPerfCPU.$pid
    snmpget -v2c -c public $ip HOST-RESOURCES-MIB::hrSWRunPerfMem.$pid
    sleep $interval;
done

Answer 6

Get Valgrind. Give it your program to run, and it'll tell you plenty about its memory usage.

This would apply only for the case of a program that runs for some time and stops. I don't know if Valgrind can get its hands on an already-running process or shouldn't-stop processes such as daemons.