[Crash-utility] x86_64 limit of 454 cpu's?

[Cliff Wickman]

Hi Dave, and company,

I get this error trying to open a dump of a large system:

crash: compressed kdump: invalid nr_cpus value: 640
crash: vmcore: not a supported file format

The message is from diskdump.c:
        if (sizeof(*header) + sizeof(void *) * header->nr_cpus > block_size ||
            header->nr_cpus <= 0) {
                error(INFO, "%s: invalid nr_cpus value: %d\n",

block_size is the page size of 4096
struct disk_dump_header looks like 464 bytes
void * is 8
So it looks like 454 is the maximum number of cpus.
           464 + 454*8 -> 4096

Is this intentional?  
It looks like a restriction that no one ever complained about. But there
are systems (Altix UV) with 2048 cpu's.

Is there an easy fix?

-Cliff