Re: [PATCH 0/3] Cleanup kdump memmap= passing and e820 usage

H. Peter Anvin
2013-01-30T22:10:21Z

On 01/30/2013 01:57 PM, Eric W. Biederman wrote:
>>
>> Yes, those seem to be the options, and we're currently discussing which one.
>>
>> The second seems to make more sense to me. The kexec tools build the
>> memory map anyway, and it makes sense to me at least to just build a
>> memory map with the appropriate regions marked as a dumpable type.
>
> This dumpable type doesn't make sense to me. Are you suggesting making
> regions that are memory but that we should not use a special memory
> type?

Yes.

> I think I would prefer that to call that new type RESERVED_MEM or
> RESERVED_CACHABLE. Being more specific is fine but dumpable certainly
> doesn't bring to mind what we are saying. Especially since we already
> communicate which areas were memory to the last kernel in an
> architecture generic format.

I was thinking that marking them differently might help debugging, at
least, but yes, we can have a RESERVED_MEM type.

However, Thomas does have a point that the current use of fairly small
positive values for Linux-defined types is a bad idea. We should use
negative types, or at least something north of 0x40000000 or so.

-hpa