On Wed, 2 Jun 2010 11:05:18 -0700 Brian Swetland <swetland@xxxxxxxxxx> wrote: > On Wed, Jun 2, 2010 at 1:06 AM, Neil Brown <neilb@xxxxxxx> wrote: > > On Wed, 2 Jun 2010 00:05:14 -0700 > > Arve Hjønnevåg <arve@xxxxxxxxxxx> wrote: > >> > The user-space suspend daemon avoids losing wake-events by using > >> > fcntl(F_OWNER) to ensure it gets a signal whenever any important wake-event > >> > is ready to be read by user-space. This may involve: > >> > - the one daemon processing all wake events > >> > >> Wake up events are not all processed by one daemon. > > > > Not with your current user-space code, no. Are you saying that you are not > > open to any significant change in the Android user-space code? That would > > make the situation a lot harder to resolve. > > There are many wakeup events possible in a typical system -- > keypresses or other input events, network traffic, telephony events, > media events (fill audio buffer, fill video decoder buffer, etc), and > I think requiring that all wakeup event processing bottleneck through > a single userspace process is non-optimal here. Just to be clear: I'm not suggesting all wake-events need to go through one process. That was just one example of how the interface I proposed could be used. There were two other examples. However one process would need to know about any wakeup event that happens. I don't think that needs to be a significant bottleneck, but I don't really know enough about all the requirement to try devising a demonstration. > > The current suspend-blocker proposal already involves userspace > changes (it's different than our existing wakelock interface), and > we're certainly not opposed to any/all userspace changes on principle, > but on the other hand we're not interested in significant reworks of > userspace unless they actually improve the situation somehow. I think > bottlenecking events through a central daemon would represent a step > backwards. I guess it becomes an question of economics for you then. Does the cost of whatever user-space changes are required exceed the value of using an upstream kernel? Both the cost and the value would be very hard to estimate in advance. I don't envy you the decision... NeilBrown -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
