RE: [PATCH v4 1/6] x86/resctrl: Parse ACPI ERDT table and map RMDD domains by L3 cache ID

[Luck, Tony]

> I do not see the need for an xarray. As new domains are created during CPU online their
> initialization can just point to the needed data, no?

Reinette,

Historical note. The xarray was added during early development on a simulator where the L3
domain numbers were wildly sparse. That turned out to be an artifact of the simulator
CPUID and BIOS interactions. On real h/w the L3 domains show up as 0, 1, 2, 3, ... 

But the xarray does still serve some purpose. Without it you’d need two passes through the
ACPI ERDT structure. One to count how many RMDD substructures are present to allocate
space, then second pass to parse things.

-Tony