linux 'top' not showing all processes

Question

I am running linux top command to see processes running inside qemu VM. Sometimes, a process does not appear in them, but if I run,

ps -eo psr,pcpu,comm | grep myprocessname

then the process is shown there. Also, such processes have low CPU utilization. Can you tell a reason of why it is so and whether it is due to the fact that processes are sleeping or something else. Thanks.

Answer 1

Top only displays the most cpu heavy tasks, take a look at the documentation.

http://linux.about.com/od/commands/l/blcmdl1_top.htm