huang ying wrote: > On 9/21/07, Mika Penttil? <mika.penttila at kolumbus.fi> 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? Thanks, Mika
