On Thursday, 3 May 2007 14:51, Paul Mackerras wrote: > Rafael J. Wysocki writes: > > > > Which is why the powermac/powerbook sleep code insists on there only > > > being one cpu active. I have an SMP powermac which can sleep; I use a > > > little script to take the second cpu down before sleeping and bring it > > > back up after waking up. > > > > That's quite intrusive. Ideally, user space processes should not notice that > > there have been a suspend at one point. > > Certainly, *most* userspace processes should not notice, and they > don't. This isn't quite true. For example, if the suspend happens while one of the 'other' processes checks how many CPUs are online, it can get a wrong result due to the suspend. > But the process initiating the suspend most certainly knows > about the suspend happening. And that's the one that arranges for > taking the second cpu down and bringing it up. Yes, obviously. > So your objection seems silly to me, unless you meant something other than > what your words seem to say. Well, perhaps I should have used some other words, then. :-) Besides, if your kernel is preemptible, the system behaves quite like an SMP one. Greetings, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
