Re: White paper on UNIX timers/timing....

From: Olaf Titz (olaf@bigred.inka.de)
Date: Sun Jun 04 2000 - 06:06:48 EST


> yet to find a nice whitepaper that explains how timing is kept inside a
> UNIX/Linux kernel with respect to wall time, jiffies, RTCs, etc. I have a
> good handle on the concepts, but would like to impart this knowledge to
> someone else and was looking for a resource or two. Anyone? TIA.

If you refer to _precision_ timekeeping, look around at www.ntp.org.
There are several papers describing the kernel synchronization model
(mostly technical however).

What's missing even there is a definite description on how the Linux
kernel handles the RTC, like the infamous question under which
circumstances the "11 minute update mode" is active. There is so much
disagreement on how best to deal with the RTC (see the hwclock(8)
manpage and the documentation in the Debian version thereof) that it
more and more seems to me the best way to handle it is to ignore it as
much as possible and solely rely on NTP...

Olaf

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Wed Jun 07 2000 - 21:00:18 EST