On Mon, 3 Mar 2014 03:11:23 +0000 Atsushi Kumagai <kumagai-atsushi at mxc.nes.nec.co.jp> wrote: > Hello Michael, > > >Hello Atsushi, > > > >On s390 we have the following little problem: > > > >We use hypervisor or stand-alone dump tools to create Linux system > >dumps. These tools do not know the kernel parameter line and dump the > >full physical memory. > > > >We use makedumpfile to filter those dumps. > > > >If a Linux system has specified the "mem=" parameter, the dump tools > >still dump the whole phypsical memory. > > I guess this is a problem of the tools, it sounds that the tools ignore > the actual memory map and just make wrong ELF headers. > How do the tools decide the range of System RAM to create ELF headers ? The tools do a physical memory detection and that defines the range of memory to be dumped and also defines the memory chunks for the ELF header. And I think we are not the only ones that have this problem. For example, the KVM virsh dump probably also has that problem. > > At least, if the tools respect the actual memory map like /proc/vmcore, it > can create correct ELF headers and makedumpfile will work normally. As I said, the tools do not know the Linux memory map. They only know the physical available memory. Michael
