On Fri, Dec 09, 2011 at 02:42:19PM +0100, Michael Holzheu wrote: > Hello Simon, > > From: Michael Holzheu <holzheu at linux.vnet.ibm.com> > > For s390 we have two modes for kdump: > > For the first mode, as on all other architectures, the kexec tool creates > the ELF header and the 2nd kernel processes it for /proc/vmcore setup. > > This mode has the disadvantage that for memory and CPU hotplug the kdump > kernel has to be reloaded by the kexec tool. For s390 this is a real problem > because we have a cpuplugd daemon that sets CPUs online and offline > according to the current workload. So CPU online/offline events occur very > often. > > For the second mode on s390, the ELF header is created by the kdump kernel. > This is done automatically when the kernel is booted in kdump mode > and no "elfcorehdr" kernel parameter is specified. On s390 the kdump kernel > can get all necessary information to build the ELF header. We can get > the memory map, all CPU registers, and vmcoreinfo > > With this patch a compile switch WITH_ELF_HEADER is introduced. When the > macro is defined, kexec will create the ELF header and add the "elfcorehdr" > kernel parameter. If it is not specified (default), no header is created. > > For s390 we want to have the 2nd mode as default because it has only > advantages for us. Thanks Michael, applied.
