From: davidsen@ariel.crd.GE.COM (william E Davidsen) Subject: Re: Process numbers Date: Thu, 1 Apr 1993 13:59:00 GMT
In article <1pcoau$mlp@agate.berkeley.edu>, dancy@uclink.berkeley.edu (Franklin Ahmon Dancy) writes:
| I just installed the cron daemon and the "at" program. At runs a program
| every minute. My process numbers are increasing rapidly. I'm wondering
| if there is a limit to how high the process numbers will go. PS lists
| 5 digits but I figure the process ids would be 4 bytes giving a limit
| of about 4 billion. What's the real scoop? Will the wrap around at
| any point or will the system croak?
The PID is a 16 bit signed number, so when they reach 32767 they
switch to floating point to increase the range. The number uses a five
bit exponent and 11+1 bit excess one mantissa.
Um, actually it's April 1, I couldn't resist, but in truth the PIDs
just wrap around with a check for duplication.
-- bill davidsen, GE Corp. R&D Center; Box 8; Schenectady NY 12345