Re: [PATCH v1 28/31] x86/resctrl: Drop __init/__exit on assorted symbols

Reinette Chatre
2024-04-09T03:32:47Z

Hi James,

On 3/21/2024 9:51 AM, James Morse wrote:
> Because ARM's MPAM controls are probed using MMIO, resctrl can't be
> initialised until enough CPUs are online to have determined the
> system-wide supported num_closid. Arm64 also supports 'late onlined
> secondaries', where only a subset of CPUs are online during boot.
>
> These two combine to mean the MPAM driver may not be able to initialise
> resctrl until user-space has brought 'enough' CPUs online.
>
> To allow MPAM to initialise resctrl after __init text has been free'd,
> remove all the __init markings from resctrl.
>
> The existing __exit markings cause these functions to be removed by the
> linker as it has never been possible to build resctrl as a module. MPAM
> has an error interrupt which causes the driver to reset and disable
> itself. Remove the __exit markings to allow the MPAM driver to tear down
> resctrl when an error occurs.

Obviously for the reasons you state this code has never been exercised.
Were you able to test this error interrupt flow yet?

Reinette