.. with the brand spanking new topology_num_nodes_per_package().

Having the topology setup determine this value during MADT/SRAT parsing before
SMP bringup avoids having to detect this situation when building the SMP
topology masks.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Chen Yu <yu.c.chen@intel.com>
Tested-by: Kyle Meyer <kyle.meyer@hpe.com>
---
 arch/x86/kernel/smpboot.c |   13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -468,13 +468,6 @@ static int x86_cluster_flags(void)
 }
 #endif
 
-/*
- * Set if a package/die has multiple NUMA nodes inside.
- * AMD Magny-Cours, Intel Cluster-on-Die, and Intel
- * Sub-NUMA Clustering have this.
- */
-static bool x86_has_numa_in_package;
-
 static struct sched_domain_topology_level x86_topology[] = {
 	SDTL_INIT(tl_smt_mask, cpu_smt_flags, SMT),
 #ifdef CONFIG_SCHED_CLUSTER
@@ -496,7 +489,7 @@ static void __init build_sched_topology(
 	 * PKG domain since the NUMA domains will auto-magically create the
 	 * right spanning domains based on the SLIT.
 	 */
-	if (x86_has_numa_in_package) {
+	if (topology_num_nodes_per_package() > 1) {
 		unsigned int pkgdom = ARRAY_SIZE(x86_topology) - 2;
 
 		memset(&x86_topology[pkgdom], 0, sizeof(x86_topology[pkgdom]));
@@ -550,7 +543,7 @@ int arch_sched_node_distance(int from, i
 	case INTEL_GRANITERAPIDS_X:
 	case INTEL_ATOM_DARKMONT_X:
 
-		if (!x86_has_numa_in_package || topology_max_packages() == 1 ||
+		if (topology_max_packages() == 1 || topology_num_nodes_per_package() == 1 ||
 		    d < REMOTE_DISTANCE)
 			return d;
 
@@ -606,7 +599,7 @@ void set_cpu_sibling_map(int cpu)
 		o = &cpu_data(i);
 
 		if (match_pkg(c, o) && !topology_same_node(c, o))
-			x86_has_numa_in_package = true;
+			WARN_ON_ONCE(topology_num_nodes_per_package() == 1);
 
 		if ((i == cpu) || (has_smt && match_smt(c, o)))
 			link_mask(topology_sibling_cpumask, cpu, i);

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     717b64d58cff6fb97f97be07e382ed7641167a56
Gitweb:        https://git.kernel.org/tip/717b64d58cff6fb97f97be07e382ed7641167a56
Author:        Peter Zijlstra <peterz@infradead.org>
AuthorDate:    Tue, 03 Mar 2026 11:55:42 +01:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 04 Mar 2026 16:35:08 +01:00

x86/topo: Replace x86_has_numa_in_package

.. with the brand spanking new topology_num_nodes_per_package().

Having the topology setup determine this value during MADT/SRAT parsing before
SMP bringup avoids having to detect this situation when building the SMP
topology masks.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Chen Yu <yu.c.chen@intel.com>
Tested-by: Kyle Meyer <kyle.meyer@hpe.com>
Link: https://patch.msgid.link/20260303110100.123701837@infradead.org
---
 arch/x86/kernel/smpboot.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 5cd6950..db3e481 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -468,13 +468,6 @@ static int x86_cluster_flags(void)
 }
 #endif
 
-/*
- * Set if a package/die has multiple NUMA nodes inside.
- * AMD Magny-Cours, Intel Cluster-on-Die, and Intel
- * Sub-NUMA Clustering have this.
- */
-static bool x86_has_numa_in_package;
-
 static struct sched_domain_topology_level x86_topology[] = {
 	SDTL_INIT(tl_smt_mask, cpu_smt_flags, SMT),
 #ifdef CONFIG_SCHED_CLUSTER
@@ -496,7 +489,7 @@ static void __init build_sched_topology(void)
 	 * PKG domain since the NUMA domains will auto-magically create the
 	 * right spanning domains based on the SLIT.
 	 */
-	if (x86_has_numa_in_package) {
+	if (topology_num_nodes_per_package() > 1) {
 		unsigned int pkgdom = ARRAY_SIZE(x86_topology) - 2;
 
 		memset(&x86_topology[pkgdom], 0, sizeof(x86_topology[pkgdom]));
@@ -550,7 +543,7 @@ int arch_sched_node_distance(int from, int to)
 	case INTEL_GRANITERAPIDS_X:
 	case INTEL_ATOM_DARKMONT_X:
 
-		if (!x86_has_numa_in_package || topology_max_packages() == 1 ||
+		if (topology_max_packages() == 1 || topology_num_nodes_per_package() == 1 ||
 		    d < REMOTE_DISTANCE)
 			return d;
 
@@ -606,7 +599,7 @@ void set_cpu_sibling_map(int cpu)
 		o = &cpu_data(i);
 
 		if (match_pkg(c, o) && !topology_same_node(c, o))
-			x86_has_numa_in_package = true;
+			WARN_ON_ONCE(topology_num_nodes_per_package() == 1);
 
 		if ((i == cpu) || (has_smt && match_smt(c, o)))
 			link_mask(topology_sibling_cpumask, cpu, i);