[SOLVED] How to find total memory used by a process?

ddenial · 11-12-2018, 02:21 AM

Hello

I need to find the total memory used by the Google Chrome browser. How to get that? The top command shows the processes individually but not total.

What I've come up with is this

Code:

$ pmap $(pidof "chrome") | tail -n1 | awk '{print $2}'
1620660K

Not sure how much accurate is this.

Any other method(s) that I can find the total memory used by Chrome browser?

Thanks

lougavulin · 11-12-2018, 04:02 AM

pmap seems to be the most accurate and still quite simple way to do.
But I think :

Code:

pmap -x PID

is easier.

Otherwise, you will need to use a profiler like valgrind.

syg00 · 11-12-2018, 04:53 AM

Into the rabbit hole ...
Try this instead - and see if you can figure out what you really want to know.

Code:

ps -C chrome -o uid,pid,rss,vsz,comm

berndbausch · 11-12-2018, 05:35 AM

You can also use top:

Code:

PID  USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
3292 stack     20   0 2010648  82940   8708 S   5.6  1.0  12:51.49 ceilometer-agen

Now the million dollar question is - what does "total memory" mean? Virtual memory (VIRT)? Physical memory (RES)? Does it include shared memory (SHR)? You decide.

EDIT I didn't read your question thoroughly. You want to sum up the memory usage of all chrome processes, which top is not really the right tool for.

ddenial · 11-12-2018, 08:44 AM

Quote:

Originally Posted by berndbausch

You can also use top:

Code:

PID  USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
3292 stack     20   0 2010648  82940   8708 S   5.6  1.0  12:51.49 ceilometer-agen

Now the million dollar question is - what does "total memory" mean? Virtual memory (VIRT)? Physical memory (RES)? Does it include shared memory (SHR)? You decide.

EDIT I didn't read your question thoroughly. You want to sum up the memory usage of all chrome processes, which top is not really the right tool for.

Just Physical memory (RES).

ddenial · 11-12-2018, 08:47 AM

Quote:

Originally Posted by syg00

Into the rabbit hole ...
Try this instead - and see if you can figure out what you really want to know.

Code:

ps -C chrome -o uid,pid,rss,vsz,comm

I guess I've to write a shell script that clips the third column and add it to find the sum. No built-in command exist?

ddenial · 11-12-2018, 09:07 AM

I've come up with this command. Is this the correct way? Is there a way to display RSS in bytes rather that default kb?

Code:

$ ps -C chrome -o comm,rss
COMMAND           RSS
chrome          226852
chrome          35500
chrome          10652
chrome          66652
chrome          38940
chrome          48032
chrome          144332
chrome          45944
chrome          72816
chrome          54748
chrome          79804
chrome          51564
chrome          114244
chrome          108788
chrome          86808
chrome          99424
chrome          121960
chrome          61384
chrome          74092
chrome          131356
chrome          23444

$ ps --no-headers -C chrome -o rss | awk '{ hr=$1*1024 ; printf("%15d\n",hr) }' | paste -sd+ | bc | numfmt --to=iec
1.7G

lougavulin · 11-12-2018, 09:21 AM

I have always heard that ps was not the good tool to know how much memory use a process.

And I guess this is why :
Man ps :

Quote:

The SIZE and RSS fields don't count some parts of a process including the page tables, kernel
stack, struct thread_info, and struct task_struct. This is usually at least 20 KiB of memory
that is always resident. SIZE is the virtual size of the process (code+data+stack).

That's why I prefer pmap.

ddenial · 11-12-2018, 09:26 AM

Quote:

Originally Posted by lougavulin

I have always heard that ps was not the good tool to know how much memory use a process.

And I guess this is why :
Man ps :

That's why I prefer pmap.

Even I was wondering why three different results.

Code:

$ free -h
              total        used        free      shared  buff/cache   available
Mem:           7.6G        1.6G        4.1G         24M        1.8G        5.6G
Swap:          8.0G          0B        8.0G

$ ps --no-headers -C chrome -o rss | awk '{ hr=$1*1024 ; printf("%15d\n",hr) }' | paste -sd+ | bc | numfmt --to=iec
2.2G

$ pmap $(pidof "chrome") | tail -n1 | awk '{print $2}'
1575424K

JeremyBoden · 11-12-2018, 03:55 PM

I tried this with two times firefox running (one of which has two tabs open):-

Code:

free -h
              total        used        free      shared  buff/cache   available
Mem:           7.7G        1.3G        3.1G        129M        3.3G        6.0G
Swap:          4.0G          0B        4.0G

ps --no-headers -C firefox -o rss | awk '{ hr=$1*1024 ; printf("%15d\n",hr) }' | paste -sd+ | bc | numfmt --to=iec
536M

pmap $(pidof "firefox") | tail -n1 | awk '{print $2}'
3098548K

All completely different!

ddenial · 11-12-2018, 11:35 PM

I think I finally figured it out on how to get an almost precise total memory of a group of processes.

Google-Chrome with 5 tabs open, each with OneNote online notebook, 1 instance of Gedit text editor and 1 instance of gnome-terminal.

Code:

$ free -h
              total        used        free      shared  buff/cache   available
Mem:           7.6G        1.9G        5.0G         30M        643M        5.3G
Swap:          8.0G          0B        8.0G

$ sudo smem -tk -U $USER -P chrome
  PID User     Command                         Swap      USS      PSS      RSS 
 6616 testr    /opt/google/chrome/chrome-s        0   116.0K   149.0K   680.0K 
 6620 testr    /opt/google/chrome/chrome-s        0   120.0K   153.0K   688.0K 
 6623 testr    /opt/google/chrome/chrome -        0   120.0K   815.0K    10.4M 
 6621 testr    /opt/google/chrome/nacl_hel        0   860.0K   875.0K     1.7M 
 7391 testr    /opt/google/chrome/chrome -        0     4.5M     5.4M    23.2M 
 6618 testr    /opt/google/chrome/chrome -        0     3.7M     8.3M    34.7M 
 6751 testr    /opt/google/chrome/chrome -        0     9.0M    10.5M    38.6M 
 7019 testr    /opt/google/chrome/chrome -        0     9.6M    11.3M    40.7M 
 6764 testr    /opt/google/chrome/chrome -        0    14.5M    16.5M    47.8M 
 6830 testr    /opt/google/chrome/chrome -        0    14.7M    16.7M    48.1M 
 6795 testr    /opt/google/chrome/chrome -        0    15.2M    16.8M    46.1M 
 6820 testr    /opt/google/chrome/chrome -        0    17.5M    19.7M    52.3M 
 6823 testr    /opt/google/chrome/chrome -        0    30.7M    32.5M    63.0M 
 6813 testr    /opt/google/chrome/chrome -        0    32.0M    34.9M    70.4M 
 6649 testr    /opt/google/chrome/chrome -        0    30.6M    39.0M    63.3M 
 7124 testr    /opt/google/chrome/chrome -        0    69.1M    71.4M   105.2M 
 6972 testr    /opt/google/chrome/chrome -        0    77.2M    79.6M   114.0M 
 6771 testr    /opt/google/chrome/chrome -        0    82.9M    85.0M   117.0M 
 6608 testr    /opt/google/chrome/chrom           0   188.2M   196.3M   230.8M 
 7308 testr    /opt/google/chrome/chrome -        0   209.6M   214.8M   261.9M 
 7140 testr    /opt/google/chrome/chrome -        0   216.4M   221.6M   269.0M 
 7359 testr    /opt/google/chrome/chrome -        0   220.1M   225.4M   272.8M 
 7219 testr    /opt/google/chrome/chrome -        0   220.4M   225.6M   272.9M 
 6720 testr    /opt/google/chrome/chrome -        0   220.4M   225.9M   273.7M 
-------------------------------------------------------------------------------
   24 1                                           0     1.6G     1.7G     2.4G

Closing Google-Chrome and after waiting 10 seconds,

Code:

$ free -h
              total        used        free      shared  buff/cache   available
Mem:           7.6G        292M        6.7G         11M        615M        7.0G
Swap:          8.0G          0B        8.0G

So, this one deducted chrome memory properly.

@JeremyBoden, can you test with Firefox, as I don't use firefox.

Thanks

pan64 · 11-13-2018, 01:48 AM

I would say no, that is not true. I suggest you to read this: www.linuxatemyram.com just to understand better how memory is handled.
Furthermore the used ram may change during the script you use, so probably that (the result) is simply outdated immediately.

syg00 · 11-13-2018, 02:05 AM

Quote:

Originally Posted by ddenial

I think I finally figured it out on how to get an almost precise total memory of a group of processes.

Good for you - I'd forgotten about smem to be honest.
pss is provided by the kernel (these days) to apportion shared library usage to users, rather than charging everybody who has a reference for the full amount of every library. There are a couple of utilities that attempt to report it - be happy with the one you found.