default or selected kernelversion does not have config value CONFIG_RESCTRL_FS.
Result is shown for kernelversion 6.16-rc7

CPU Resource Control Filesystem (resctrl)

modulename: rdtgroup.ko

configname: CONFIG_RESCTRL_FS

Linux Kernel Configuration
└─>File systems
└─>Miscellaneous filesystems
└─>CPU Resource Control Filesystem (resctrl)
In linux kernel since version 6.1.145 (release Date: 2025-07-14)  
Some architectures provide hardware facilities to group tasks and
monitor and control their usage of memory system resources such as
caches and memory bandwidth. Examples of such facilities include
Intel's Resource Director Technology (Intel(R) RDT) and AMD's
Platform Quality of Service (AMD QoS).

If your system has the necessary support and you want to be able to
assign tasks to groups and manipulate the associated resource
monitors and controls from userspace, say Y here to get a mountable
'resctrl' filesystem that lets you do just that.

If nothing mounts or prods the 'resctrl' filesystem, resource
controls and monitors are left in a quiescent, permissive state.

On architectures where this can be disabled independently, it is
safe to say N.

See <file:Documentation/filesystems/resctrl.rst> for more information.

source code: