Re: Where does 10ms serial port read latency come from?

Alan Cox (alan@lxorguk.ukuu.org.uk)
Tue, 20 Oct 1998 04:56:27 +0100 (BST)

> I've found nothing relevant in the linux docs, except perhaps for the
> 100Hz kernel scheduling timer, though since there's no process between
> mine and the serial port, i can't see how that matters.

Linux dumps serial line data into buffers and does the line processing
every 100th of a second. For normal use that gives exceptional efficiency,
good scaling and good cache locality while avoiding the scheduler
thrashing between tasks.

On the negative side it screws what you are trying to do rather completely.

Alan

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