From: Alison Schofield <alison.schofield@xxxxxxxxx>
Commit fd49f99c1809 ("ACPI: NUMA: Add a node and memblk for each
CFMWS not in SRAT") did not account for the case where the BIOS
only partially describes a CFMWS Window in the SRAT. That means
the omitted address ranges, of a partially described CFMWS Window,
do not get assigned to a NUMA node.
Replace the call to phys_to_target_node() with numa_add_memblks().
Numa_add_memblks() searches an HPA range for existing memblk(s)
and extends those memblk(s) to fill the entire CFMWS Window.
Extending the existing memblks is a simple strategy that reuses
SRAT defined proximity domains from part of a window to fill out
the entire window, based on the knowledge* that all of a CFMWS
window is of a similar performance class.
*Note that this heuristic will evolve when CFMWS Windows present
a wider range of characteristics. The extension of the proximity
domain, implemented here, is likely a step in developing a more
sophisticated performance profile in the future.
There is no change in behavior when the SRAT does not describe
the CFMWS Window at all. In that case, a new NUMA node with a
single memblk covering the entire CFMWS Window is created.
Fixes: fd49f99c1809 ("ACPI: NUMA: Add a node and memblk for each CFMWS not in SRAT")
Signed-off-by: Alison Schofield <alison.schofield@xxxxxxxxx>
---
drivers/acpi/numa/srat.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
index 1f4fc5f8a819..12f330b0eac0 100644
--- a/drivers/acpi/numa/srat.c
+++ b/drivers/acpi/numa/srat.c
@@ -310,11 +310,16 @@ static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
start = cfmws->base_hpa;
end = cfmws->base_hpa + cfmws->window_size;
- /* Skip if the SRAT already described the NUMA details for this HPA */
- node = phys_to_target_node(start);
- if (node != NUMA_NO_NODE)
+ /*
+ * The SRAT may have already described NUMA details for all,
+ * or a portion of, this CFMWS HPA range. Extend the memblks
+ * found for any portion of the window to cover the entire
+ * window.
+ */
+ if (!numa_fill_memblks(start, end))
return 0;
+ /* No SRAT description. Create a new node. */
node = acpi_map_pxm_to_node(*fake_pxm);
if (node == NUMA_NO_NODE) {
--
2.37.3
