Re: [PATCH 10/28] i386: map enough initial memory to create lowmem mappings

H. Peter Anvin
2007-04-19T21:11:56Z

Andi Kleen wrote:
> On Thursday 19 April 2007 22:55:50 H. Peter Anvin wrote:
>> Andi Kleen wrote:
>>>> Is some version of this going in for 2.6.21, or is it not a real problem?
>>> When it's only seen with Xen it's not a real problem right now.
>> It's not just seen only with Xen, though. It will affect all kernels in
>> a particular range of sizes, and we have ordinary kernels covering that
>> range (in fact, Xen hardly affects size in that way.)
>
> Then we would have seen reports surely?

The critical size window is relatively small, though. The size of the
uncompressed kernel mod 4 MB must be above 3.75 MB or so. If you have
less than 1 GB RAM, the window is even smaller. This is strictly
configuration-dependent, and has nothing to do with Xen. It just so
happened that the first people to detect and diagnose it (as opposed to
just "it doesn't boot") were Xen people.

-hpa