Messages in this thread | | | Date | Wed, 23 Feb 2000 08:11:09 -0500 (EST) | From | "Richard B. Johnson" <> | Subject | Re: PID Wrap <strangeness> |
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On Wed, 23 Feb 2000, Mathijs Mohlmann wrote:
> > On Tue, Feb 22, 2000 at 05:31:51PM -0500, Richard B. Johnson wrote: > > On Linux 2.3.41 (haven't checked others) when the PID wraps past > > 32,767 the next PID is 300. It is not the next-available low one. > > > > Does anybody know why? > > For speed, since a lot of pids lower than 300 are used by daemons, > there's no need to check them. This will speedup the get_pid > function after a wrap. > > me >
The lowest numbered pid, not currently in use, can be readily obtained when a task exits. The task exit is currently the slowest thing to do because of the wait-for-status requirement. Adding a variable and a comparison at process exit would get the number for free.
A hard-coded number of 300 is an eye-opener.
Cheers, Dick Johnson
Penguin : Linux version 2.3.41 on an i686 machine (800.63 BogoMips).
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