Re: CVS commit: src

[David Holland <dholland-sourcechanges%netbsd.org@localhost>]

On Tue, Jul 29, 2014 at 05:53:59AM -0400, Greg Troxel wrote:
 > >> Also, note in the ucom(4) man page that there is about 1 ms of
 > >> latency.  Discussed on tech-kern in October of 2013, with the only
 > >> concern being that someone who didn't know what they were doing might
 > >> set up a stratum 1 server, and that somehow might have worse
 > >> timekeeping than whatever else that person might have done; the man
 > >> page comment is a mitigation for this.
 > >
 > > latency of 1ms and the same jitter - only ucycom uses interrupt
 > > endpoints for data transfer
 > 
 > I was abstracting on purpose, because no other man page describes
 > performance characteristics in such detail.  (When I tested, my best
 > guess was that the delay from PPS edge capture ranged from 400us to
 > 1400us as the USB frame clock shifted.)

In few other cases does it matter at this level either...

-- 
David A. Holland
dholland%netbsd.org@localhost