Vishnu Yadav, If you don't see reserved memory region on mips in /proc/iomem than it is definitely kernel issue. You can check: 1. you have continuous memory segment, which is enough for booting new kernel in low 512M. (In general you can reserve memory at any address but kernel can be booted if it is in lower 512M), 2. you specified right crashkernel= option. And it points to real memory segment. 3. crashkernel was parsed right in the kernel. dmesg |grep mem - will print existence memory segments in format X(memory size) @(at) Y(memory address). cat /proc/iomem - should show that memory is really reserved. If you don't see reserved segments then you have to debug how kernel reserves area for crashkernel (BOOT_MEM_RESERVED). Best regards, Maxim Uvarov. 2010/2/22 Simon Horman <horms at verge.net.au>: > On Thu, Jan 28, 2010 at 06:36:07PM +0530, Vishnu Yadav wrote: >> Hi >> I am ?not able to reserve the memory in mips 64 plateform for "crash kernel" >> >> in below function of arch/mips/kernel/setup.c file of kernel code >> reserve_bootmem(start, size , flags) >> if i put flags= BOOTMEM_DEFAULT then this function succeeds but doesnt >> reserve ?mem of crash kernel .. i verified it by seeing /proc/iomem >> >> but if i put flags= BOOTMEM_EXCLUSIVE .. this function itself fails and >> again no memry is reseved. >> >> >> Pls suggest me how to resevre mem regio for "crash kernel" in mips 64. NOTE- >> I have applied kernel as well as user spaces patches for running kexec on >> mips64. > > Does Maxim Uvarov's recent patch help you at all? > > http://lists.infradead.org/pipermail/kexec/2010-February/003816.html > -- Best regards, Maxim Uvarov