what about having network connections inhibit sleep?

[Ricardo Carrano]

On Wed, Jun 4, 2008 at 10:41 PM, C. Scott Ananian <cscott at cscott.net> wrote:
> On Wed, Jun 4, 2008 at 7:12 PM, John Gilmore <gnu at toad.com> wrote:
>>> what do people think about the idea of making the existance of established
>>> TCP connections inhibit sleep?
>>
>> What release are you running?  Auto-suspend isn't enabled in production releases.
>>
>> Joyride should be awakened from suspend by any received unicast (TCP) packet,
>> so I'm not sure why you saw it hang in mid-download, if the update was one long
>> continuous TCP download.  But if it's rsync, maybe it's driven from the client
>> end (and if the client suspends, the server never sends anything further).
>
> olpc-update should be touching /etc/inhibit-suspend before it does its
> work, so it should not be sleeping.  If it does, and your build was
> not ancient, it's a bug and I'd like to know more.
>
>> The real fix is to only force a suspend when the kernel knows no
>> process is scheduled to run now or soon, and ato waken in less than a
>> whole second.  We're slowly working on those issues.  If we keep
>> kludging things like TCP, there's never the time to put in the real fixes.
>
> Yes.  Better integration of suspend and the kernel scheduler is
> discussed near the end of
> http://download.laptop.org/content/conf/20080403-olpc-mini-conf/Power/
> but I don't think we've made any measurable progress on it since then.
>  Dilinger has been resyncing us with upstream, and deepak just started
> full-time OLPC work.  We could use help!
>  --scott

Some updates on suspend/resume from the perspective of its
interactions with network traffic:

1 - XOs are now capable of waking up when receiving multicast frames.
This is necessary for collaboration to work. Use 'ethtool -s' to
change wol configuration and activate the "m" flag.

2 - XOs will soon implement a signature based filter that will allow
the creation of arbitrary filters to wake the XO (necessary, for
instance, to wake on ARP). This is ready in the firmware and a driver
patch is being worked. Tests with a first version of the driver were
successful. Those interested, please check
http://dev.laptop.org/ticket/6993#comment:3

I agree that we still have a lot of testing to do before turning idle
suspend on by default. Those interested in testing with an unofficial
driver (that supports the signature based filter), while the official
one is not available can download a kernel rpm at:
http://dev.laptop.org/~rcarrano/kernel-2.6.22-20080515.1.olpc.0_carrano.i586.rpm

Finally, tests in wireless should be performed with update-1.706+ (or
at least the latest version of joyride). Anything older than that will
be not very useful since many things were fixed or improved in recent
driver/firmware versions.

Cheers!
Ricardo