Is there a way to group similar processes when using tools like top/htop? Sometimes I just want to know what's eating my memory and some programs (browsers mostly) are using multiple processes, which makes it hard to read how much RAM they really use.
So far I came up only with something like that:
ps ax -o pmem,cmd | grep opera | grep -oE '^[ ]*[0-9.]+' | paste -sd+ - | bc
You can use ps -C to only display process information for a particular command name.
e.g.
ps -C opera
You can then use other ps options to extract just the data you are looking for. In particular, h or --no-headers to suppress the column headers, and -o pmem to show the percentage of memory used by the process.
ps -C opera --no-headers -o pmem
That will give you a bunch of memory-usage percentages, one per line.
There are numerous methods for summing data like that, one of the methods I use frequently is to pipe it into xargs to convert it into one line with elements delimited by spaces, then into sed to convert spaces to + symbols, and then into bc to perform the calculation. Your method of piping into paste -sd+ works as well or arguably better than | xargs | sed.
Putting that all together, you get:
ps -C opera --no-headers -o pmem | xargs | sed -e 's/ /+/g' | bc
or
ps -C opera --no-headers -o pmem | paste -sd+ | bc
In other words, you can use ps -C instead of multiple greps if you just want data about one particular running program.
NOTE: You can use multiple -C options on the same command line if you want info about more than one program at a time. e.g.
ps -C iceweasel -C chromium -C opera
ps h -C java -o pmem,args | awk '/foo/ {print $1}' | ... e.g. to look for a java program called foo.
From inside top you can use the following:
Press SHIFT+f
Press the Letter corresponding to %MEM
Press ENTER
You might also try:
ps -eo pmem,pcpu,vsize,pid,cmd | sort -k 1 -nr | head -5
This command will give the top 5 processes by memory usage.
I hope you find this info helpful!
You can make a shell script
#!/bin/bash
Total=`cat /proc/meminfo | head -n1 | awk '{print $2}'`
max_usage=`ps ax -o pmem,fname | sort -r | head -n2 | tail -n1 | awk '{print $1}'`
name=`ps ax -o pmem,fname | sort -r | head -n2 | tail -n1 | awk '{print $NF}'`
echo "$Total $max_usage $name"
echo "($max_usage*$Total)/(100*1024)" | bc
This will give the highest mem usage Application.
sed -e 's/^[[:space:]]*//' should fix it. Also does your script adds up memory usage of processes with same command?
This can be simplified with termsql.
ps -C chromium-browser -o pmem | termsql -1 "SELECT SUM([%MEM]) FROM tbl"
Note, that currently it's not upload to PyPI, and also can only be installed system-wide (setup.py is a little broken), like sudo pip install https://github.com/tobimensch/termsql/archive/master.zip.
termsql is available on PyPI, and can be installed e.g. with pipx install termsql.
