Re: [RFC] [PATCH 2.6.19-rc4] kdump panics early in boot when reserving MP Tables located in high memory

[Andi Kleen <ak@suse.de>]

[Finally dropping that annoying fastboot list from cc. Please never include any closed 
mailing lists in l-k posts. Thanks]

>   That won't worked because in arch/86_64/kernel/e820.c, the exactmap
> parsing clobbers end_pfn_map.

That's a bug imho. It shouldn't do that.

end_pfn_map should be always the highest address in e820 so that we 
can access all firmware tables safely.

-Andi

> 
> static int __init parse_memmap_opt(char *p)
> {
> 	char *oldp;
> 	unsigned long long start_at, mem_size;
> 
> 	if (!strcmp(p, "exactmap")) {
> #ifdef CONFIG_CRASH_DUMP
> 		/* If we are doing a crash dump, we
> 		 * still need to know the real mem
> 		 * size before original memory map is
> 		 * reset.
> 		 */
> 		saved_max_pfn = e820_end_of_ram();
> #endif
> 		end_pfn_map = 0;
> 		e820.nr_map = 0;
> 		userdef = 1;
> 		return 0;
> 	}