On Sat, Jul 12, 2008 at 11:02:17AM +1000, Nigel Cunningham wrote: > Hi. > > On Fri, 2008-07-11 at 16:11 -0400, Vivek Goyal wrote: > > Hi Andrew, > > > > We can use this patchset for hibernation, but can it be a better way of doing > > things than what we already have, I don't know. Last time I had raised > > this question and power people had various views. In the end, Pavel wanted > > this patchset to be in. Pavel, can tell more here... > > > > To me this patchset looks interesting for couple of reasons. > > > > - Looks like an interesting feature where one can have a separate kernel > > in memory and one can switch between the kernels on the fly. It can > > be modified to have more than one kernel in memory at a time. > > I'm not sure how useful that would be, though. I already have > functionality in TuxOnIce which allows you to resume a different image > instead of powering off (roughly the same thing when combined with not > removing the image after resuming). It was neat when testing to be able > to switch back and forth, and I developed the code because I imagined > that it could form part of the foundation for switching between a login > screen and users' stored sessions. Is this what you're imagining? > I did not think of that. I thought of two things. - This can possibly be used for non-disruptive kernel crash dumping, where if a user wants to capture the snapshot of kernel and then continue to work. Thought, it might be little heavy weight solution and kernel state also has changed a bit by the time dump is captured (because of all the suspend code). - One can have two distributions installed on a single system and switch between two booted kernels in few seconds. > > - So far kexec was one directional. One can only kexec to new kernel and > > old kernel was gone. Now this patchset makes kexec functionality kind > > of bidirectional and this looks like logical extension and can lead > > to intersting use cases in future. > > Ah. You mean keeping both kernels in memory at the same time? In the > above, I was replacing one image with another. Yes, here both the kernels will remain in the RAM. In fact it should be easily possible to keep more than 2 kernels in memory and switch between these. Thanks Vivek _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
