Re: [PATCH] dax/kmem: add build config for protected dax memory blocks

[Andrew Morton]

On Wed, 14 Jan 2026 21:42:22 -0500 Gregory Price <gourry@xxxxxxxxxx> wrote:

> Since this protection may break userspace tools, it should
> be an opt-in until those tools have time to update to the
> new daxN.M/hotplug interface instead of memory blocks.
> 
> --- a/drivers/dax/Kconfig
> +++ b/drivers/dax/Kconfig
> @@ -78,4 +78,22 @@ config DEV_DAX_KMEM
>  
>  	  Say N if unsure.
>  
> +config DEV_DAX_KMEM_PROTECTED

Users must rebuild and redeploy kernels after having updated a
userspace tool.  They won't thank us for this ;)

Isn't there something we can do to make this feature
backward-compatible?