Re: [PATCH v2 1/3] acpi: Add acpi_map_pxm_to_online_node()

Toshi Kani
2015-06-19T01:16:58Z

On Fri, 2015-06-19 at 02:42 +0200, Rafael J. Wysocki wrote:
> On Tuesday, June 09, 2015 05:10:38 PM Toshi Kani wrote:
> > The kernel initializes CPU & memory's NUMA topology from ACPI
> > SRAT table. Some other ACPI tables, such as NFIT and DMAR,
> > also contain proximity IDs for their device's NUMA topology.
> > This information can be used to improve performance of these
> > devices.
> >
> > This patch introduces acpi_map_pxm_to_online_node(), which maps
> > a given pxm to an online node. This allows ACPI device driver
> > modules to obtain a node from a device proximity ID. Unlike
> > acpi_map_pxm_to_node(), this interface is guaranteed to return
> > an online node so that the caller module can use the node without
> > dealing with the node status. A node may be offline when a device
> > proximity ID is unique, SRAT memory entry does not exist, or
> > NUMA is disabled (ex. numa_off on x86).
> >
> > This patch also moves the pxm range check from acpi_get_node()
> > to acpi_map_pxm_to_node().
:
> > +/*
> > + * Return an online node from a pxm. This interface is intended for ACPI
> > + * device drivers that obtain device NUMA topology from ACPI table, but
> > + * do not initialize the node status.
> > + */
>
> Can you make this a proper kerneldoc, please? *Especially* that it is an
> exported function.
>
> The description is a bit terse too in my view.

Agreed. I will update the comment as a proper kerneldoc.

Thanks!
-Toshi