RE: [PATCH] x86, sched: Allow NUMA nodes to share an LLC on Intel platforms

From: Luck, Tony
Date: Tue Feb 09 2021 - 20:28:47 EST


> +#define X86_BUG_NUMA_SHARES_LLC X86_BUG(25) /* CPU may enumerate an LLC shared by multiple NUMA nodes */

During internal review I wondered why this is a "BUG" rather than a "FEATURE" bit.

Apparently, the suggestion for "BUG" came from earlier community discussions.

Historically it may have seemed reasonable to say that a cache cannot span
NUMA domains. But with more and more things moving off the motherboard
and into the socket, this doesn't seem too weird now.

-Tony