Hi John, Thanks for the comments and early catch on this.
Robert and wireless/collaboration experts, Can you comment on this? There are a couple of relevant requirements and known issues documented here: http://wiki.laptop.org/go/Feature_roadmap/Improved_battery_life It sounds like we need a solid design proposal which defines exactly how/when the wireless uses power and how/when the XO wakes up. Any links or suggestions welcome. Thanks, Greg S John Gilmore wrote: > In 9.1.0, auto-suspend is going to be on by default, which we estimate > will roughly triple our battery life. We're working on fixing all the > bugs that would prevent that. > > One of them is not strictly a bug -- it's a performance issue. The > Presence Service sends packets frequently, for tracking the presence > of your friends and any shared activities. Many of these are > multicast packets (some are probably unicast jabber packets, too). > > In 8.2.0, with auto-suspend enabled, you have to run a specific command > to enable suspended laptops to awaken when multicast packets arrive; > see bug #6818 and run "ethtool -s msh0 wol um". This will become the > default in 9.1.0. > > The problem I can foresee is that the Presence Service will send > packets so frequently that everyone's laptop will always be waking up, > negating the power-stretching abilities of auto-suspend. This seems > to occur with only a few laptops around (in my tests at home); yet > we need to make it work with dozens of laptops within range, for > our deployments. > > I hope that the Collabora team is running in this mode now, and > working out ways to reduce packet traffic to let sleeping laptops lie. > The cellular phone industry went through several cycles of design > improvements like this, enabling today's remarkable phone battery > life, without impact on our ability to rapidly communicate whenever > desired. OLPC hasn't yet done the first round of such improvements, > and I hope it WILL do so before 9.1.0. We could all use those long > battery lives -- especially the kids in the rural deployments. We > don't want to tell them to turn off collaboration if they want their > laptop to last all day; it's one of our key features. > > John > > > > _______________________________________________ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel