On Wednesday, 11 July 2007 06:11, Al Boldi wrote: > Jeremy Fitzhardinge wrote: > > Jeremy Maitin-Shepard wrote: > > > In > > > addition, I recall that the Linux boot procedure on x86 and on some > > > other platforms necessarily uses certain low-address memory, like the > > > first 640K, which must be backed up regardless. > > > > Well, the traditional framebuffer/ISA space between 640k and 1M probably > > needs to be identity mapped, but I don't think there's anything in there > > which specifically needs to be save/restored (except framebuffer > > contents, maybe?). > > > > > For these reasons, it seems that it would be easiest to simply backup > > > the first e.g. 16 or 64 MB of memory, and not have to worry about > > > loading the kernel at a non-standard address and specifying a > > > complicated exact memmap. Someone might prove me wrong, though. > > > > Yes, I suppose. You're certain the old kernel's devices are completely > > quiescent at that point? > > That's exactly the problem; trying to save a state from within the kernel > would probably necessitate a freezer hack, which we are trying so dearly to > avoid.
Well, I don't think that avoiding the freezer whatever it takes would be a good idea. There needs to be some balance. ;-) > The only way the kexec approach may be successful, is by completely relying > on the kexec'd hibernate-mode kernel to save state, otherwise we would be > back to square one. And if that required a special boot procedure for the > kexec'd hibernate-mode kernel, then why not? Because such things are very difficult for many users. My experience with the userland suspend shows that clearly. Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
