On Friday, February 25, 2011, Jan Beulich wrote: > >>> On 23.02.11 at 12:10, Ian Campbell <Ian.Campbell@xxxxxxxxxxxxx> wrote: > > On Wed, 2011-02-23 at 10:58 +0000, Jan Beulich wrote: > >> >>> On 23.02.11 at 10:08, Ian Campbell <Ian.Campbell@xxxxxxxxxxxxx> wrote: > >> > On Wed, 2011-02-23 at 07:27 +0000, Shriram Rajagopalan wrote: > >> >> Make XEN_SAVE_RESTORE user visible and enable HIBERNATION and SWAP, > >> >> if this option is enabled. > >> > > >> > I was under the (perhaps mistaken?) impression that selecting user > >> > visible Kconfig symbols was verboten since it has side-effects which > >> > make it hard for users to figure out why something cannot be switched > >> > off and/or how to turn things on etc. > >> > > >> > In any case I think I preferred the "depends HIBERNATION" idea -- I > >> > thought that was the consensus of the thread too? > >> > >> Why HIBERNATION (and SWAP) instead of SUSPEND? Xen doesn't > >> support the former (other than the latter)... > > > > HIBERNATION provides the FREEZE, THAW and RESUME methods which we would > > like to use to integrate save/restore/checkpoint with the PM core i.e. > > choose THAW vs. RESUME based on whether the suspend was cancelled (aka a > > checkpoint) or not. See Shriram's other recent patch for details. > > But imo it's nevertheless wrong to select HIBERNATION (and bogus > to select SWAP), as that'll create to user space the impression that > the kernel is capable of doing hibernation, which is wrong. If you > need the particular PM operations but no hibernation, then an > intermediary option will need to be introduced. I think we can introduce CONFIG_HIBERNATE_INTERFACE that will be user-visible option instead of CONFIG_HIBERNATION and will select the latter. Then, CONFIG_XEN_SAVE_RESTORE will also be able to select CONFIG_HIBERNATION without building the hibernate interface in, which will prevent user space from being confused, but that will cause too much code to be built anyway. Thanks, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
