On Wed, May 01, 2013 at 12:38:17AM +0200, Rafael J. Wysocki wrote: > On Tuesday, April 30, 2013 05:25:42 PM Konrad Rzeszutek Wilk wrote: > > > > After the 'restore_registers' it returns and we end up called > > > > restore_processor_state() - where we reload the GDT. The reload of > > > > the GDT is not needed as bootup kernel has already loaded the GDT which > > > > is at the same physical location as the the restored kernel. > > > > > > I'm not sure if this particular statement is actually correct. It is correct > > > on 32-bit, but here it is not necessary for the bootup kernel to be the same > > > as the image one. Different kernel version may be used for that even (at > > > least theoretically). So the question is, and I'm quite unsure about the > > > answer, if the GDT of from the bootup kernel is really *guaranteed* to be > > > at the same location (given that those kernels may be really different). > > > > A bit of testing with different bootup kernel provided me with this error: > > PM: Image mismatch: version > > This implies that you tested on an architechture without > CONFIG_ARCH_HIBERNATION_HEADER. > > > which after a bit of digging pointed me to 'check_image_kernel'. The criteria > > there imply that the different kernel versions or releases cannot be used with > > hibernation. > > Only if CONFIG_ARCH_HIBERNATION_HEADER is unset, which is not the case for > CONFIG_X86_64. OK, Let me play on 64-bit later on this week and see if the patch I cobbled up to save/restore the GDT in the booting kernel properly works. -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html