On Tuesday 05 January 2010, Bartłomiej Zimoń wrote: > Dnia 5 stycznia 2010 22:23 "Rafael J. Wysocki" <rjw@xxxxxxx> napisał(a): > > On Tuesday 05 January 2010, Bartłomiej Zimoń wrote: > > > Dnia 5 stycznia 2010 10:07 Anders Eriksson <aeriksson@xxxxxxxxxxx> napisał(a): > > > > > > > > rjw@xxxxxxx said: > > > > >> > I don't see a problem with this in principle, although I don't think signals > > > > >> > are very suitable for this particular purpose, because you need two-way > > > > >> > communication between the power manager and the processes it's going to > > > > >> > notify (because it has to wait for the processes to finish their preparations > > > > >> > and to tell it that they are ready). > > > > > > > > Wouldn't there need to be dependecy tracking for the userspace processes? A > > > > process couldn't signal "done" until it know there's no more work to do, which > > > > requires all other processes to finish up first. > > > > > > > > > > Not all processes will need pm notification. > > > > > > Just in case, could this "power manager" be provided as userspace > > > driver for kernel (for example compiled as UIO)? > > > > I don't really understand why you want to do that in the kernel. Is there > > any particular reason why this cannot be done in the user space? > > > > Problem is with notification from pm-utils. Dbus for session is only > user session waid and it is almost imposible to send something > from systembus or it needs lots of magic. Don't use dbus, then. > Even if i'll use pm-utils, must provide way to notify my app. > Looks like no standard way here, that's bad, every app has it's own? Isn't there a possibility to introduce a standard way of doing that without involving the kernel directly? > I think this way - if kernel is processes manager and if it sends > "some unknown" signal to every process before kernel suspend so why > not send sepcific and known signal instread. We _can_ do that, but what would a process be supposed to do after receiving such a signal? > But now we have DeviceKit-power/upower whatever but it doesn't provide > this feature or something simmilar to relay on. You're still not saying what you really need. So, what's the application you have in mind that needs a notification from the _kernel_ so badly? Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
