On ?t 18-05-06 19:25:29, David Brownell wrote: > On Thursday 18 May 2006 1:50 pm, Pavel Machek wrote: > > > Well, will it ever go to sleep? In such case? There are many things > > that wake up periodically. > > Applications that constantly wake/poll are death to power management anyway, > that's not news ... most of the "work" done by polling is wasted. When they > get switched to no-timeout/blocking APIs, then they can sleep painlessly > until a relevant wakeup event triggers. Well, that is not how X app currently work :-(. > Things that really *must* wake up periodically should be using some API that > interacts with RTC alarms, and those RTC alarms should be acting as system > wakeup events. But that means completely rewriting userspace. > There's also non-automated sleep too ... what "apmsleep" used to do when > you told it to suspend until 7am (or for two hours, etc). The same thing > can be done with /sys/power/state and a wakeup-enabled RTC. Yep, I should get it working one day. > > > As for downloading, that's why ethernet adapters have wake-on-lan (WOL) > > > mechanisms. Likewise for other wakeup-capable devices, like a keyboard > > > or mouse. Or even 3D engines, DSPs, SPUs, ... > > > > ?? WOL is for different functionality, I'm afraid. Or do you know > > ethernet hub that automagically wakes machines when data come? > > No, that's exactly what WOL is designed for. A typical scenarios has > the adapter waking up when the incoming packet is unicast to the MAC > address of that host. The hub/switch would act normally. I do not think WOL wakes that way. IIRC it needs magic ethernet packet. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
