Re: [PATCH] ACPI: add a boot parameter to disable parsing CFMWS during NUMA init

[Gregory Price <gourry@gourry.net>]

On Wed, Mar 04, 2026 at 04:06:47PM +0800, Haifeng Xu wrote:
> For the machine Intel(R) Xeon(R) 6746E that supports CXL memory,
> the possible nodes are 20 (0-19). However, only two numa nodes (0-1)
> have memory and the rest nodes (2-19) detected by CEDT are memoryless.
> 
> The problems is that when creating many pods, the shrinker map size
> needs to be expanded for all memory cgroups in expand_shrinker_info().
> If the number of possible nodes is too large, the holding time of
> shrinker lock grows significantly.
> 
> In this case, there is no CXL memory inserted in the machine, those
> memoryless nodes are useless for us, so there is no need to set them
> in 'numa_nodes_parsed'. After disabling parsing CFMWS, the pod creation
> time is reduced from over 10 minutes to approximately 150 seconds in
> our internal test.
> 

This seems like the wrong scope to fix the underlying problem - which is
the shrinker lock holding scope.

If you're not actually using CXL, can't you just disable CXL in the
BIOS?  Then you shouldn't even emit CFMWS at all.

~Gregory