On Friday, 13 July 2007 16:37, Alan Stern wrote: > On Fri, 13 Jul 2007, Rafael J. Wysocki wrote: > > > > I missed this discussion. is this idea to suspend, write to disk, but > > > leave things in ram so that if you wakeup soon enough you have everything > > > for ram, but if you don't and the battery dies you can restore from disk? > > > > > > if so I think it's a mistake to mix the two. it would be better to just > > > suspend to ram, and wake up once in a while to check the battery state and > > > when the battery gets low enough do the suspend to disk. > > > > > > otherwise you end up mixing the requirements of the two types of suspend, > > > which is how things got so ugly in the first place. > > > > Not necessarily. If we don't put devices into low power states before creating > > the image, that should work just fine (quiesce devices, create the image or > > kexec the new kernel, reprobe devices, save the image, suspend to RAM, > > resume from RAM, continue - or restore from the image if power failed in the > > meantime). Still, for this purpose, both kernels need to be able to handle the > > same set of devices. > > Why? > > Suppose the kexec kernel can't handle some device. The normal kernel > has already quiesced the device, so it will remain quiescent while the > kexec kernel runs and throughout the suspend. When the regular kernel > regains control the device will be ready for use. I don't see any > problem. On an ACPI system the device may be in a power state that doesn't allow us to enter S3 (in theory, that is). Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
