Dave Jiang 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
> node_set_perf_attrs() for the various attributes where nodeX is matched
> to the NUMA node of the CXL region.
>
> Cc: Rafael J. Wysocki <rafael@xxxxxxxxxx>
> Reviewed-by: Alison Schofield <alison.schofield@xxxxxxxxx>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> Tested-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
> ---
> v7:
> - Fix typo is commit log. (Jonathan)
> ---
> drivers/acpi/numa/srat.c | 11 +++++++++++
> drivers/base/node.c | 1 +
> drivers/cxl/core/cdat.c | 5 +++++
> drivers/cxl/core/core.h | 1 +
> drivers/cxl/core/region.c | 7 ++++++-
> include/linux/acpi.h | 9 +++++++++
> 6 files changed, 33 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
> index 0214518fc582..e45e64993c50 100644
> --- a/drivers/acpi/numa/srat.c
> +++ b/drivers/acpi/numa/srat.c
> @@ -29,6 +29,8 @@ static int node_to_pxm_map[MAX_NUMNODES]
> unsigned char acpi_srat_revision __initdata;
> static int acpi_numa __initdata;
>
> +static int last_real_pxm;
> +
> void __init disable_srat(void)
> {
> acpi_numa = -1;
> @@ -536,6 +538,7 @@ int __init acpi_numa_init(void)
> if (node_to_pxm_map[i] > fake_pxm)
> fake_pxm = node_to_pxm_map[i];
> }
> + last_real_pxm = fake_pxm;
> fake_pxm++;
> acpi_table_parse_cedt(ACPI_CEDT_TYPE_CFMWS, acpi_parse_cfmws,
> &fake_pxm);
> @@ -547,6 +550,14 @@ int __init acpi_numa_init(void)
> return 0;
> }
>
> +bool acpi_node_backed_by_real_pxm(int nid)
> +{
> + int pxm = node_to_pxm(nid);
> +
> + return pxm <= last_real_pxm;
> +}
> +EXPORT_SYMBOL_GPL(acpi_node_backed_by_real_pxm);
I quibble with this naming because it is not about "real" vs "fake" is
about HMAT decorated PXMs vs not, but I do not want to hold up v6.9
consideration for this quibble.
It can be addressed when / if cxl_need_node_perf_attrs_update() ever
interoperates with a non ACPI platform.
