RE: [RFC 2/3] x86/numa: Introduce numa_remove_memblks(node, start, end)

[Dan Williams <dan.j.williams@intel.com>]

alison.schofield@ wrote:
> From: Alison Schofield <alison.schofield@intel.com>
> 
> Add support for removing memblks from numa_meminfo that are
> within a start/end range, and of a node.
> 
> numa_add_memblk() allows in kernel users to add a memblk to
> a NUMA node. There is no method exposed to remove a memblk.
> 
> The use case here is to allow the ACPI driver to remove
> redundant memblks when it knows they exist, rather than
> implementing a cleanup that needlessly walks all memblks
> during a cleanup phase.

Again this assumes a particular way to solve the memblk update problem,
it's not clear that a remove method is the way to go versus an update
method.

I.e. its not clear to me where the "redundant" memblks appear.


> numa_cleanup_meminfo() exists for merging memblks, however,
> it only considers adjacent memblks, and, it actually moves the
> memblks to numa_reserved_meminfo, before doing the cleanup.

So either the algorithm for solving the extend memblks when they overlap
CFMWS needs to be described here, or this patch needs to be squashed.