Re: [PATCH v10 02/17] x86/resctrl: Require 64-bit x86 for resctrl support

[Reinette Chatre]

Hi Tony,

On 7/29/26 10:27 AM, Tony Luck wrote:
> From: Chen Yu <yu.c.chen@xxxxxxxxx>
> 
> All known hardware that supports Intel RDT or AMD QoS is 64-bit. Future
> enhancements like MMIO-based Enhanced RDT (ERDT) monitoring require
> readq()/writeq() which are only available on 64-bit. There is also no
> realistic use case for users to build a 32-bit kernel on a server and

I find the "no realistic use case" statement quite bold. Would a 32-bit kernel
not have same needs for resource allocation as a 64-bit kernel?

nit: server -> system
(since RDT is not limited to servers)

> enable resctrl.
> 
> Drop 32-bit support by changing the X86_CPU_RESCTRL dependency from X86
> to X86_64.
> 
> Since X86_CPU_RESCTRL now implies X86_64, remove the redundant X86_64
> dependency from X86_CPU_RESCTRL_INTEL_AET.
> 
> Tested-by: Hongyu Ning <hongyu.ning@xxxxxxxxxxxxxxx>
> Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
> Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
> ---

I support this change but I would just like to ensure the motivation is
accurate.

Reinette