Re: [PATCH v12 07/25] x86/resctrl: Update special case for Intel Haswell enumeration

[Reinette Chatre]

Hi Tony,

On 9/16/26 4:13 PM, Tony Luck wrote:
> Certain Intel Haswell CPUs have support for resctrl L3 cache allocation
> but do not enumerate the feature. There is a quirk to check for support
> and provide hard-coded parameters. This quirk sets rdt_alloc_capable
> to indicate to get_rdt_alloc_resources() that normal enumeration is
> not needed.
> 
> Drop setting of rdt_alloc_capable in cache_alloc_hsw_probe() in
> preparation for removal of this global variable.

The changelog just states "Drop setting of rdt_alloc_capable" without
any explanation *why* it is ok to do so. Consider something like this draft:

	Certain Intel Haswell CPUs support resctrl L3 cache allocation but do
	not enumerate the feature. A quirk probes for support and provides
	hard-coded parameters. The quirk sets both the global rdt_alloc_capable
	and the resource specific rdt_resource::alloc_capable, only the
	global is used to signal that normal enumeration can be skipped.

	The global rdt_alloc_capable is redundant since rdt_resource::alloc_capable
	already	carries the same information.

	Stop setting rdt_alloc_capable in the quirk and rely on the resource
	specific flag to prepare for removal of this global variable.

	No functional change intended.

> 
> Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
> ---
Patch looks good to me.

Reinette