Re: [Lse-tech] Re: [rfc][patch] Memory Binding API v0.3 2.5.41

William Lee Irwin III
2002-10-15T01:06:50Z

On Mon, 2002-10-14 at 17:38, Matthew Dobson wrote:
>> Also, right now, memblks map to nodes in a straightforward manner (1-1
>> on NUMA-Q, the only architecture that has defined them). It will likely
>> look the same on most architectures, too.

On Mon, Oct 14, 2002 at 05:55:53PM -0700, john stultz wrote:
> Just an FYI: I believe the x440 breaks this assumption.
> There are 2 chunks on the first CEC. The current discontig patch for it
> has to drop the second chunk (anything over 3.5G on the first CEC) in
> order to work w/ the existing code. However, that will probably need to
> be addressed at some point, so be aware that this might affect you as
> well.

MAP_NR_DENSE()-based zone-relative pfn to zone->zone_mem_map index
remapping is designed to handle this (and actually more severe
situations). The only constraint is that pfn's must be monotonically
increasing with ->zone_mem_map index. Some non-i386 architectures
virtually remap physical memory to provide the illusion of contiguity
of kernel virtual memory, but in a mature port (e.g. i386) there's high
risk of breaking numerous preexisting drivers.

Bill