top 使い方

Shift+o: 表示された特定のキーを押してEnterすると任意の列でソートできる
Shift+p: CPU使用率順にソート
Shift+m: メモリ使用率順にソート


■Shift+o
Current Sort Field:  Q  for window 1:Def
Select sort field via field letter, type any other key to return

  a: PID        = Process Id
  b: PPID       = Parent Process Pid
  c: RUSER      = Real user name
  d: UID        = User Id
  e: USER       = User Name
  f: GROUP      = Group Name
  g: TTY        = Controlling Tty
  h: PR         = Priority
  i: NI         = Nice value
  j: P          = Last used cpu (SMP)
  k: %CPU       = CPU usage
  l: TIME       = CPU Time
  m: TIME+      = CPU Time, hundredths
  n: %MEM       = Memory usage (RES)
  o: VIRT       = Virtual Image (kb)
  p: SWAP       = Swapped size (kb)
* Q: RES        = Resident size (kb)
  r: CODE       = Code size (kb)
  s: DATA       = Data+Stack size (kb)
  t: SHR        = Shared Mem size (kb)
  u: nFLT       = Page Fault count
  v: nDRT       = Dirty Pages count
  w: S          = Process Status
  x: COMMAND    = Command name/line
  y: WCHAN      = Sleeping in Function
  z: Flags      = Task Flags <sched.h>

Note1:
  If a selected sort field can't be
  shown due to screen width or your
  field order, the '<' and '>' keys
  will be unavailable until a field
  within viewable range is chosen.

Note2:
  Field sorting uses internal values,
  not those in column display.  Thus,
  the TTY & WCHAN fields will violate
  strict ASCII collating sequence.
  (shame on you if WCHAN is chosen)

Thanks...
http://qiita.com/k0kubun/items/7368c323d90f24a00c2f