callout patch - make callouts per-cpu and MP safe.

[Matthew Dillon]

:Patch is at http://leaf.dragonflybsd.org/~joerg/changes_vs_matt.diff
:Just apply it after Matt's changes to i386/i386/machdep.c, kern/kern_clock.c,
:kern_kern_timeout.c and sys/callout.c.
:
:It uses still callout internally and the overhead of the additional entries
:in struct timeout can be reduced by altering the callout implementation,
:but it should be enough to illustrate the perpuse.
:
:Joerg

    I do not want to add another API to the timeout code until we remove one
    of the two API's we already have (i.e. remove timeout() & untimeout()).
    I reall don't.

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>