On Mon, Nov 05, 2007 at 05:19:44PM -0800, H. Peter Anvin wrote:Andi Kleen wrote:There really are only two ways to deal with this -- drop the memory (which should be automated, and a warning printed) or adjust the MTRRs. The problem is that at some point we run out of MTRRs, partially because they're masks instead of base/limit.Jesse Barnes (cc:d) wrote a patch to address this, I think (x86: trimIt wasn't merged because it broke booting on some systems.
memory not covered by WB MTRRs), but as far as I can tell it hasn't
been merged yet. System is Intel, 4gb of RAM.
Besides the memory would be still lost -- all it did was to automate
the "mem=XXXX" line.
Just out of curiosity, what would be the problem if the MTRRs covered more
than the memory size ? For instance, instead of having 512 MB at 4G, why
not have 1G at 4G ?