Re: [PATCH 1/2] x86/resctrl: Add io_alloc_min_cbm_all interface for CBM reset

[Aaron Tomlin]

On Mon, Nov 10, 2025 at 10:34:48AM -0600, Babu Moger wrote:
> Does the following option work for you?
> 
> # echo "*=0" > /sys/fs/resctrl/info/L3/io_alloc_cbm
> 
> 
> Here,|*| represents all domains.

Hi Babu,

Thank you for your response.

Unfortunately, this approach will not work.

If I understand correctly, the assumption that echo 0 (which translates to
a CBM of all zeros) would always be accepted as a "minimum" value is
incorrect since r->cache.min_cbm_bits could be greater than zero
(e.g., under Intel hardware). See rdt_init_res_defs_intel().

The goal is not just to "clear" the CBM, but to reset it to the smallest
valid mask.



Kind regards,
-- 
Aaron Tomlin