daemon help

[John F Haugh II]

In article <1991Feb07.072540.28435 at convex.com> tchrist at convex.COM (Tom Christiansen) writes:
>I don't really suggest this.  It's probably not worth it.  Should your
>whole system wait just so you can get a better snapshot of the proc
>table?

You should be able to slurp the entire proc table in one read from
/dev/kmem atomically. (Except on certain platforms which actually
do have pre-emptive scheduling ...) The transfer would be memory to
memory.  Even my slow, stupid, 68K box does about 4MB/s, so a 32KB
proc table (which is plenty big on stupid PC's) would transfer in
about 8ms.  Certain fields (wait channel, for example) won't be
accurate because of interrupt servicing, but the time fields should
all be perfectly fine.  I don't know how fast my 386 is, but I'm
sure it is still much slower than a Convex C220 ;-)
-- 
John F. Haugh II                             UUCP: ...!cs.utexas.edu!rpp386!jfh
Ma Bell: (512) 832-8832                           Domain: jfh at rpp386.cactus.org
"I've never written a device driver, but I have written a device driver manual"
                -- Robert Hartman, IDE Corp.