Re: [PATCH v5 12/12] cxl/region: Deal with numa nodes not enumarated by SRAT

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Tue, 6 Feb 2024 15:28:40 -0700
Dave Jiang <dave.jiang@intel.com> wrote:

> For the numa nodes that are not created by SRAT, no memory_target is
> allocated and is not managed by the HMAT_REPORTING code. Therefore
> hmat_callback() memory hotplug notifier will exit early on those NUMA
> nodes. The CXL memory hotplug notifier will need to call
> node_set_perf_attrs() directly in order to setup the access sysfs
> attributes.
> 
> In acpi_numa_init(), the last proximity domain (pxm) id created by SRAT is
> stored. Add a helper function acpi_node_backed_by_real_pxm() in order to
> check if a NUMA node id is defined by SRAT or created by CFMWS.
> 
> node_set_perf_attrs() symbol is exported to allow update of perf attribs
> for a node. The sysfs path of
> /sys/devices/system/node/nodeX/access0/initiators/* is created by
> ndoe_set_perf_attrs() for the various attributes where nodeX is matched
node

> to the NUMA node of the CXL region.
> 
> Cc: Rafael J. Wysocki <rafael@kernel.org>
> Reviewed-by: Alison Schofield <alison.schofield@intel.com>
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Trivial comment inline.
Otherwise LGTM

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
> v5:
> - Fix ARM compile of missing prototype (0day)
> ---



> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index 19e419f18472..db51e35cb44f 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -3084,7 +3084,12 @@ static bool cxl_region_update_coordinates(struct cxl_region *cxlr, int nid)
>  
>  	for (int i = 0; i < ACCESS_COORDINATE_MAX; i++) {
>  		if (cxlr->coord[i].read_bandwidth) {
> -			rc = cxl_update_hmat_access_coordinates(nid, cxlr, i);
> +			rc = 0;
> +			if (cxl_need_node_perf_attrs_update(nid))
> +				node_set_perf_attrs(nid, &cxlr->coord[i], i);
maybe
continue;
here
> +			else
> +				rc = cxl_update_hmat_access_coordinates(nid, cxlr, i);
> +

Then no need to indent the above

>  			if (rc == 0)
>  				cset++;
>  		}