On Thu, May 27, 2010 at 07:59:02PM +0200, Thomas Gleixner wrote: > On Thu, 27 May 2010, Matthew Garrett wrote: > > ACPI provides no guarantees about what level of hardware functionality > > remains during S3. You don't have any useful ability to determine which > > events will generate wakeups. And from a purely practical point of view, > > since the latency is in the range of seconds, you'll never have a low > > enough wakeup rate to hit it. > > Right, it does not as of today. So we cannot use that on x86 > hardware. Fine. That does not prevent us to implement it for > architectures which can do it. And if x86 comes to the point where it > can handle it as well we're going to use it. Where is the problem ? If > x86 cannot guarantee the wakeup sources it's not going to be used for > such devices. The kernel just does not provide the service for it, so > what ? We were talking about PCs. Suspend-as-c-state is already implemented for OMAP. > So the only thing you are imposing to app writers is to use an > interface which solves nothing and does not save you any power at > all. It's already been demonstrated that the Android approach saves power. > Runnable tasks and QoS guarantees are the indicators whether you can > go to opportunistic suspend or not. Everything else is just window > dressing. As I keep saying, this is all much less interesting if you don't care about handling suboptimal applications. If you do care about them then the Android approach works. Nobody has demonstrated a scheduler-based one that does. -- Matthew Garrett | mjg59@xxxxxxxxxxxxx _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
