There are dump mechansims like s390 stand-alone dump or KVM virsh dump that write the physical memory of a machine and that are not aware of the dumped operating system. If for the Linux kernel of the dumped system the "mem=" kernel parameter has been specified, the "max_mapnr" that makedumpfile gets from the ELF header can be bigger than the maximum page frame number used by the dumped Linux kernel. This can lead to makedumpfile errors on s390x and can also lead to extended dump times and sizes. The following two patches for version 1.5.5 fix these issues: Michael Holzheu (2): makedumpfile: Fix zero checking of get_mm_sparsemem() makedumpfile: Use max_pfn from mem_map array makedumpfile.c | 36 ++++++++++++++++++++++++++++++------ 1 file changed, 30 insertions(+), 6 deletions(-)