New XO-1.5 10.2.0 build 112

[James Cameron]

On Sun, Mar 14, 2010 at 07:34:14PM -0400, Paul Fox wrote:
> i've been thinking about this problem, and i'm not sure i
> understand how seamless network connectivity is _supposed_ to
> work, in the face of suspend and wake-on-lan.

Classic Wake on LAN is an entirely different technology to what we are
trying.

What we want is most of the time spent in suspend, if there is no reason
to wake, and to wake if there is reason.

Reasons to wake that we are handling are:
- incoming network packet,
- user input.

Reasons to wake that we are not handling are:
- TCP timer expiry, (e.g. a retry on an active connection, where a
  segment we have sent hasn't been acknowledged),
- application timer expiry (e.g. a ping from the laptop to another
  host, or some other application level network timer),

And as you point out, we are probably not deferring a wake when a packet
is ready to be sent.

> don't we also need a "don't-go-to-sleep-because-i-still-might-have
> something-to-send" feature?

Heh.

> a simple "how busy is the network?" mode won't be sufficient, i
> don't think.

Agreed, this could be an intractable problem.  It may require more
thought.  You've started, let's proceed.

One workaround is to merely wake up once a minute for a second or
two.  This will allow TCP to emit what it should, and allow user space
processes to get through their event or timing loops.

-- 
James Cameron
http://quozl.linux.org.au/