Clock drift

tags:

• hardware
• clock
• drift

A post on python-dev by Neil McLaren caught my eye today:

A signal sent while the operating system is doing certain things to

the application (including, sometimes, when it is swapped out or

deep in I/O.)

That sounds like an outright bug. I can’t think

of any earthly reason why the handler shouldn’t

be called eventually, if it remains installed and

the process lives long enough.

See above. It gets lost at a low level. That is why you can cause

serious time drift on an “IBM PC” (most modern ones) by hammering

the video card or generating streams of floating-point fixups. Most

people don’t notice, because xntp or equivalent fixes it up.

Neil McLaren

If you’ve been wondering why the clock drift on your PC seems so

bad, perhaps this is part of the problem?

In my next blog post, I intend to detail setting up dual-path

routing to take advantage of the peculiarities of the South African ISP

market to save yourself some money if you are using an ADSL

connection.