On Sunday, 9 of December 2007, Pavel Machek wrote: > Hi! > > > This patch implements the functionality of jumping between the kexeced > > kernel and the original kernel. > > > > To support jumping between two kernels, before jumping to (executing) > > the new kernel and jumping back to the original kernel, the devices > > are put into quiescent state, and the state of devices and CPU is > > saved. After jumping back from kexeced kernel and jumping to the new > > kernel, the state of devices and CPU are restored accordingly. The > > devices/CPU state save/restore code of software suspend is called to > > implement corresponding function. > > > > To support jumping without reserving memory. One shadow backup page > > (source page) is allocated for each page used by new (kexeced) kernel > > (destination page). When do kexec_load, the image of new kernel is > > loaded into source pages, and before executing, the destination pages > > and the source pages are swapped, so the contents of destination pages > > are backupped. Before jumping to the new (kexeced) kernel and after > > jumping back to the original kernel, the destination pages and the > > source pages are swapped too. > > > > A jump back protocol for kexec is defined and documented. It is an > > extension to ordinary function calling protocol. So, the facility > > provided by this patch can be used to call ordinary C function in real > > mode. > > > > A set of flags for sys_kexec_load are added to control which state are > > saved/restored before/after real mode code executing. For example, you > > can specify the device state and FPU state are saved/restored > > before/after real mode code executing. > > > > The states (exclude CPU state) save/restore code can be overridden > > based on the "command" parameter of kexec jump. Because more states > > need to be saved/restored by hibernating/resuming. > > > > Signed-off-by: Huang Ying <ying.huang@xxxxxxxxx> > > I'm not kexec hacker... but maybe this is in good enough state to be > merged? It is useful on its own: kexec jump and back means we can dump > system then continue running, for example... As far as I'm concerned, patches [1/4] and [2/4] can go. The other two are not in that shape yet (especially the [3/4] patch). Greetings, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
