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| author |   Dan Williams <dan.j.williams@intel.com> | 2020-02-16 12:00:48 -0800 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2020-02-17 10:49:06 -0800 |
| commit | b2ca916ce392a9d4cea3489a3efb2b627b839eaf (patch) | |
| tree | e60ba3dc33b63e5645c504680d1aba6759cb1bcb /include/linux/acpi.h | |
| parent | Linux 5.6-rc1 (diff) | |
| download | wireguard-linux-b2ca916ce392a9d4cea3489a3efb2b627b839eaf.tar.xz wireguard-linux-b2ca916ce392a9d4cea3489a3efb2b627b839eaf.zip | |
ACPI: NUMA: Up-level "map to online node" functionality
The acpi_map_pxm_to_online_node() helper is used to find the closest
online node to a given proximity domain. This is used to map devices in
a proximity domain with no online memory or cpus to the closest online
node and populate a device's 'numa_node' property. The numa_node
property allows applications to be migrated "close" to a resource.
In preparation for providing a generic facility to optionally map an
address range to its closest online node, or the node the range would
represent were it to be onlined (target_node), up-level the core of
acpi_map_pxm_to_online_node() to a generic mm/numa helper.
Cc: Michal Hocko <mhocko@suse.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/158188324802.894464.13128795207831894206.stgit@dwillia2-desk3.amr.corp.intel.com
Diffstat (limited to 'include/linux/acpi.h')
| -rw-r--r-- | include/linux/acpi.h | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 0f24d701fbdc..3839363081f3 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -416,9 +416,30 @@ extern void acpi_osi_setup(char *str); extern bool acpi_osi_is_win8(void); #ifdef CONFIG_ACPI_NUMA -int acpi_map_pxm_to_online_node(int pxm); int acpi_map_pxm_to_node(int pxm); int acpi_get_node(acpi_handle handle); + +/** + * acpi_map_pxm_to_online_node - Map proximity ID to online node + * @pxm: ACPI proximity ID + * + * This is similar to acpi_map_pxm_to_node(), but always returns an online + * node. When the mapped node from a given proximity ID is offline, it + * looks up the node distance table and returns the nearest online node. + * + * ACPI device drivers, which are called after the NUMA initialization has + * completed in the kernel, can call this interface to obtain their device + * NUMA topology from ACPI tables. Such drivers do not have to deal with + * offline nodes. 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. + */ +static inline int acpi_map_pxm_to_online_node(int pxm) +{ + int node = acpi_map_pxm_to_node(pxm); + + return numa_map_to_online_node(node); +} #else static inline int acpi_map_pxm_to_online_node(int pxm) { |