diff mbox series

[tip:,x86/mm] ACPI/NUMA: Apply SRAT proximity domain to entire CFMWS window

Message ID 169456081810.27769.10707287336222746575.tip-bot2@tip-bot2
State New
Headers
Series [tip:,x86/mm] ACPI/NUMA: Apply SRAT proximity domain to entire CFMWS window |

Commit Message

tip-bot2 for Thomas Gleixner Sept. 12, 2023, 11:20 p.m. UTC 
  The following commit has been merged into the x86/mm branch of tip:

Commit-ID:     8f1004679987302b155f14b966ca6d4335814fcb
Gitweb:        https://git.kernel.org/tip/8f1004679987302b155f14b966ca6d4335814fcb
Author:        Alison Schofield <alison.schofield@intel.com>
AuthorDate:    Mon, 10 Jul 2023 13:02:59 -07:00
Committer:     Dave Hansen <dave.hansen@linux.intel.com>
CommitterDate: Tue, 12 Sep 2023 16:13:34 -07:00

ACPI/NUMA: Apply SRAT proximity domain to entire CFMWS window

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")
Reported-by: Derick Marks <derick.w.marks@intel.com>
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Derick Marks <derick.w.marks@intel.com>
Link: https://lore.kernel.org/all/eaa0b7cffb0951a126223eef3cbe7b55b8300ad9.1689018477.git.alison.schofield%40intel.com
---
 drivers/acpi/numa/srat.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
index 1f4fc5f..12f330b 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) {