>It's been brought to my attention that more efficient callout handling
>would be beneficial, not only for the current uses of callouts, but
>even more so in cases where it might be preferrable to have a *huge*
>number of callouts at once.

>Does anyone have suggestions on further refinements to this, or
>perhaps better ways of doing it?

Did you look at http://www.cs.wustl.edu/~amc/research/timer/,
"New Callout and Timer Facilities for NetBSD" by Adam Costello?
This is based on the timing wheel algorithm designed in 1987 
by George Varghese and Tony Lauck (in fact, Varghese and Lauck are
referenced in the 4.3BSD book in chapter 3, around page 53.)

I believe there is a tech report on it at 
http://www.cs.wustl.edu//cs/techreports/1995/wucs-95-23.ps.Z
Hope that is useful.

chuck
-- 
>>Chuck Cranor, Graduate Student, Computer and Communications Research Center<<
>>Washington University, St. Louis MO    http://www.ccrc.wustl.edu/pub/chuck <<
... help!  my wife has accepted a job with at&t research in new jersey and
    now i've got to find a job in new jersey too ...