On Mon, May 06, 2013 at 03:09:55PM +0200, Michael Holzheu wrote: > Hello Vivek, > > For s390 we want to use /proc/vmcore for our SCSI stand-alone > dump (zfcpdump). We have support where the first HSA_SIZE bytes are > saved into a hypervisor owned memory area (HSA) before the kdump > kernel is booted. When the kdump kernel starts, it is restricted > to use only HSA_SIZE bytes. > Hi Michael, Hatayama is changing /proc/vmcore interface to support mmap(). Can you please rebase your changes on top of those patches. http://thread.gmane.org/gmane.linux.kernel/1477622 Secondly, I think /proc/vmcore does not have to know whether elf headers are in old memory or new memory. Given that s390 is taking a deviation, so it now becomes an arch specific detail. Can't we just create few arch specific helper functions to retrieve and free elf headers. - arch_get_crash_headers() - All arch except return elfcorehdr_add except s390. - arch_read_crash_header_data() - All arch just call into read_from_oldmem() except s390. We can provide a generic implementation in /proc/vmcore.c so all other arch can use that generic implementation. Or use symbol override trick. - arch_free_crash_headers() - All arch do nothing except s390 which can reclaim the memory for elf headers prepared. Generic code has parsed/copied the headers by now. What do you think? Above 3 calls should solve the problem and allow arch to handle elf headers differently. And generic implementation still keeps common logic for processing headers. Thanks Vivek
