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All cpu

Press 1.

Full process string

Press c.

Show swap

Press f, use arrow keys to move to SWAP, press space bar to select, press esc. Swap will show on the right hand side.

Sort by something

Press f, move to the field you want to sort by, press s to sort then esc.

View number of threads and sort by it

Press f, move to nTH, press speacebar to choose, press s to sort, press esc.

Sort by memory

Press M.

Sort by CPU

Press P.

Sort by Pid

Press N.

Time running

Press T for highest time. Press M for highest mem used and time.

Display only for one user

$ top -u <user>

All idle processes

Press i.

Change priority of a process (renice)

Press r <pid>, type range -20 to 19. -20 is the highest priority.