Arve Hjønnevåg <arve@xxxxxxxxxxx> writes: > > PM: Opportunistic suspend support. > > Power management features present in the current mainline kernel are > insufficient to get maximum possible energy savings on some platforms, > such as Android, because low power states can only safely be entered > from idle. Suspend, in its current form, cannot be used, since wakeup > events that occur right after initiating suspend will not be processed > until another possibly unrelated event wake up the system again. I think the problems with wakeups in the current suspend path need to be described in more detail. In particular, why check_wakeup_irqs() is not enough etc. > On some systems idle combined with runtime PM can enter the same power > state as suspend, but periodic wakeups increase the average power > consumption. Suspending the system also reduces the harm caused by > apps that never go idle. On other systems suspend can enter a much > lower power state than idle. > > To allow Android and similar platforms to save more energy than they > currently can save using the mainline kernel, we introduce a mechanism > by which the system is automatically suspended (i.e. put into a > system-wide sleep state) whenever it's not doing useful work, called > opportunistic suspend. A definition of "useful work" here would provide clarity and would also help clarify by what criteria other on-going work is determined to be not useful. Kevin _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
