pidstat - Report statistics for Linux tasks/processes.

FORMAT
       pidstat [ -C comm ] [ -d ] [ -I ] [ -p { pid | SELF | ALL } ] [ -r ] [ -t ] [ -T { TASK | CHILD | ALL } ] [ -u ] [ -V ] [ -w ] [ interval [ count ] ]

DESCRIPTION
       The pidstat command is used for monitoring individual tasks currently being managed by the Linux kernel.  

It writes to standard output activities for every  task  selected with option -p or for every task managed by the Linux kernel if option -p ALL has been used.

Not selecting any tasks is equivalent to specifying -p ALL but only active tasks (tasks with non-zero statistics values) ... Read more »