"H. Peter Anvin" <hpa at zytor.com> writes: > 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. Yes. It doesn't much matter in the kernel but when it because part of the ABI it is a real issue. Since old kernels treat any value they don't understand as reserved passing a modified e820 map seems reasonable to me once we have reserved a special linux value for it. Eric
