Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [tip:x86/paravirt] x86-64, gdt: Store/ load GDT for ACPI S3 or hibernate/resume path is not needed. | Date | Wed, 01 May 2013 00:38:17 +0200 |
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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.
Thanks, Rafael
-- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.
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