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 _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
