How to see top processes sorted by actual memory usage?

Question

I have a server with 12G of memory. A fragment of top is shown below:

PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                              


        

Answer 1

Building on gaoithe's answer, I attempted to make the memory units display in megabytes, and sorted by memory descending limited to 15 entries:

ps -e -orss=,args= |awk '{print $1 " " $2 }'| awk '{tot[$2]+=$1;count[$2]++} END {for (i in tot) {print tot[i],i,count[i]}}' | sort -n | tail -n 15 | sort -nr | awk '{ hr=$1/1024; printf("%13.2fM", hr); print "\t" $2 }'

       588.03M  /usr/sbin/apache2
       275.64M  /usr/sbin/mysqld
       138.23M  vim
        97.04M  -bash
        40.96M  ssh
        34.28M  tmux
        17.48M  /opt/digitalocean/bin/do-agent
        13.42M  /lib/systemd/systemd-journald
        10.68M  /lib/systemd/systemd
        10.62M  /usr/bin/redis-server
         8.75M  awk
         7.89M  sshd:
         4.63M  /usr/sbin/sshd
         4.56M  /lib/systemd/systemd-logind
         4.01M  /usr/sbin/rsyslogd

Here's an example alias to use it in a bash config file:

    alias topmem="ps -e -orss=,args= |awk '{print \$1 \" \" \$2 }'| awk '{tot[\$2]+=\$1;count[\$2]++} END {for (i in tot) {print tot[i],i,count[i]}}' | sort -n | tail -n 15 | sort -nr | awk '{ hr=\$1/1024; printf(\"%13.2fM\", hr); print \"\t\" \$2 }'"

Then you can just type topmem on the command line.