Re: [patch] Fix large MCA bootmem allocation

[Robin Holt <holt@sgi.com>]

On Wed, Feb 06, 2008 at 12:50:11PM +0900, Hidetoshi Seto wrote:
> Hidetoshi Seto wrote:
>> Then, I suppose we need a CPU_UP_PREPARE callback to allocate memory
>> before hot-added CPU enters cpu_init().
>
> Ah, we cannot allocate bootmem later, so it would be better to make
> the callback to return NOTIFY_BAD if (!__per_cpu_mca[hcpu]).
>

bootmem is only used for the first cpu.  The other cpus use regular
allocations.  So we should be able to do a CPU_UP_PREPARE.

Comparing the severity of allocating a ton of extra memory with the
chance that we fail on an allocation and given that there are likely
other things in the cpu_init path which are not checked, do you see the
lack of check as a show-stopper for this patch or would you accept this
patch with the plan being fixup the cpu_init path later?

Thanks,
Robin