Re: [PATCH v6 16/24] x86/resctrl: Make resctrl_mounted checks explicit

Reinette Chatre
2023-10-03T21:19:26Z

Hi James,

On 9/14/2023 10:21 AM, James Morse wrote:
> The rdt_enable_key is switched when resctrl is mounted, and used to
> prevent a second mount of the filesystem. It also enables the
> architecture's context switch code.
>
> This requires another architecture to have the same set of static-keys,
> as resctrl depends on them too. The existing users of these static-keys
> are implicitly also checking if the filesystem is mounted.
>
> Make the resctrl_mounted checks explicit: resctrl can keep track of
> whether it has been mounted once. This doesn't need to be combined with
> whether the arch code is context switching the CLOSID.
>
> rdt_mon_enable_key is never used just to test that resctrl is mounted,
> but does also have this implication. Add a resctrl_mounted to all uses
> of rdt_mon_enable_key. This will allow rdt_mon_enable_key to be swapped
> with a helper in a subsequent patch.
>
> This will allow the static-key changing to be moved behind resctrl_arch_
> calls.
>
> Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
> Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
> Tested-By: Peter Newman <peternewman@google.com>
> Signed-off-by: James Morse <james.morse@arm.com>
>
> ---

Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>

Reinette