minimal system processes

[Junior <ejr@inbox.com>]

Hi all,
Below are the processes running on my embedded ARM system.
Are all these really necessary?
How do I know what is absolutely necessary? I'm trying to determine what the system will run reliably on.
Much thanks.

  PID  Uid     VmSize Stat Command
    1 root        268 S   init       
    2 root            SWN [ksoftirqd/0]
    3 root            SW< [events/0]
    4 root            SW< [khelper]
    5 root            SW< [kthread]
   14 root            SW< [kblockd/0]
   17 root            SW< [khubd]
   52 root            SW  [pdflush]
   53 root            SW  [pdflush]
   54 root            SW< [kswapd0]
   55 root            SW< [aio/0]
  141 root            SW  [mtdblockd