On 9/21/07, Mika Penttilä <mika.penttila@xxxxxxxxxxx> wrote: > huang ying wrote: > > On 9/21/07, Mika Penttilä <mika.penttila@xxxxxxxxxxx> wrote: > > > >> huang ying wrote: > >> > >>> On 9/21/07, Mika Penttilä <mika.penttila@xxxxxxxxxxx> wrote: > >>> > >>> > >>>>> Usage: > >>>>> > >>>>> 1. Compile kernel with following options selected: > >>>>> > >>>>> CONFIG_X86_32=y > >>>>> CONFIG_RELOCATABLE=y # not needed strictly, but it is more convenient with it > >>>>> CONFIG_KEXEC=y > >>>>> CONFIG_CRASH_DUMP=y # only needed by kexeced kernel to save/restore memory image > >>>>> CONFIG_PM=y > >>>>> CONFIG_KEXEC_JUMP=y > >>>>> > >>>>> 2. Download the kexec-tools-testing git tree, apply the kexec-tools > >>>>> kjump patches (or download the source tar ball directly) and > >>>>> compile. > >>>>> > >>>>> 3. Download and compile the krestore tool. > >>>>> > >>>>> 4. Prepare 2 root partition used by kernel A and kernel B/C, referred > >>>>> as /dev/hda, /dev/hdb in following text. This is not strictly > >>>>> necessary, I use this scheme for testing during development. > >>>>> > >>>>> 5. Boot kernel compiled for normal usage (kernal A). > >>>>> > >>>>> 6. Load kernel compiled for hibernating/restore usage (kernel B) with > >>>>> kexec, the same kernel as that of 5 can be used if > >>>>> CONFIG_RELOCATABLE=y and CONFIG_CRASH_DUMP=y are selected. > >>>>> > >>>>> The --elf64-core-headers should be specified in command line of > >>>>> kexec, because only the 64bit ELF is supported by krestore tool. > >>>>> > >>>>> For example, the shell command line can be as follow: > >>>>> > >>>>> kexec -p -n /boot/bzImage --mem-min=0x100000 --mem-max=0xffffff > >>>>> --elf64-core-headers --append="root=/dev/hdb single" > >>>>> > >>>>> 7. Jump to the hibernating kernel (kernel B) with following shell > >>>>> command line: > >>>>> > >>>>> kexec -j > >>>>> > >>>>> 8. In the hibernating kernel (kernel B), the memory image of > >>>>> hibernated kernel (kernel A) can be saved as follow: > >>>>> > >>>>> cp /proc/vmcore . > >>>>> cp /sys/kernel/kexec_jump_back_entry . > >>>>> > >>>>> > >>>>> > >>>> Here we save also kernel B's pages. > >>>> > >>>> > >>> No, the kernel B's pages will not be saved. Because when we build the > >>> elfcore (/proc/vmcore) header, we exclude memory area used by kernel > >>> B. The details can be found in kexec-tools patches. > >>> > >>> > >>> > >> Ok I see. But should the kernel B's e820 mem map be limited to 1m-16m in > >> order not to allocate pages found also in A's space? Or does does the > >> --mem-min and --mem-max do that also? > >> > > > > That is what "memmap=exactmap memmap=640K@0K memmap=15M@1M" for. The > > contents of e820 memmap will be overrided when these kernel parameters > > are specified. > > > > Best Regards, > > Huang Ying > > > Yes, you just didn't specify exactmap for kernel B in your instructions, > but only for C. But it is also required for kernel B then? > They are specified for kernel B by /sbin/kexec automatically. Best Regards, Huang Ying _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
