[RFC PATCH v9 03/13] mm: Add support for eXclusive Page Frame Ownership (XPFO)

[Waiman Long]

On Wed, Apr 03, 2019 at 11:34:04AM -0600, Khalid Aziz wrote:
> diff --git a/Documentation/admin-guide/kernel-parameters.txt
b/Documentation/admin-guide/kernel-parameters.txt

> index 858b6c0b9a15..9b36da94760e 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -2997,6 +2997,12 @@
>
>      nox2apic    [X86-64,APIC] Do not enable x2APIC mode.
>
> +    noxpfo        [XPFO] Disable eXclusive Page Frame Ownership (XPFO)
> +            when CONFIG_XPFO is on. Physical pages mapped into
> +            user applications will also be mapped in the
> +            kernel's address space as if CONFIG_XPFO was not
> +            enabled.
> +
>      cpu0_hotplug    [X86] Turn on CPU0 hotplug feature when
>              CONFIG_BO OTPARAM_HOTPLUG_CPU0 is off.
>              Some features depend on CPU0. Known dependencies are:

Given the big performance impact that XPFO can have. It should be off by
default when configured. Instead, the xpfo option should be used to
enable it.

Cheers,
Longman