- s/s/seconds/

- s/10 seconds/60 seconds/

- Mention the zero-disables-it feature.

Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>