git: e2c9871f6a7b - stable/13 - arm64: Include NUMA locality info in the CPU topology

[Mark Johnston]

The branch stable/13 has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=e2c9871f6a7ba8a14b2c377a860cfaf1adcdff83

commit e2c9871f6a7ba8a14b2c377a860cfaf1adcdff83
Author:     Mark Johnston <markj at FreeBSD.org>
AuthorDate: 2021-02-18 15:50:57 +0000
Commit:     Mark Johnston <markj at FreeBSD.org>
CommitDate: 2021-02-25 13:57:08 +0000

    arm64: Include NUMA locality info in the CPU topology
    
    The scheduler uses this topology to try and preserve locality when
    migrating threads between CPUs and when performing work stealing.
    Ensure that on NUMA systems it will at least take the NUMA topology into
    account.
    
    Reviewed by:    mmel
    Submitted by:   Klara, Inc.
    Sponsored by:   Ampere Computing
    Differential Revision:  https://reviews.freebsd.org/D28579
    
    (cherry picked from commit 17d0f830dddf38724068f4139b6bef9a5dab70c5)
---
 sys/arm64/arm64/mp_machdep.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/sys/arm64/arm64/mp_machdep.c b/sys/arm64/arm64/mp_machdep.c
index 8f1118d36bf5..8d5d82879571 100644
--- a/sys/arm64/arm64/mp_machdep.c
+++ b/sys/arm64/arm64/mp_machdep.c
@@ -437,8 +437,35 @@ ipi_stop(void *dummy __unused)
 struct cpu_group *
 cpu_topo(void)
 {
+	struct cpu_group *dom, *root;
+	int i;
+
+	root = smp_topo_alloc(1);
+	dom = smp_topo_alloc(vm_ndomains);
+
+	root->cg_parent = NULL;
+	root->cg_child = dom;
+	CPU_COPY(&all_cpus, &root->cg_mask);
+	root->cg_count = mp_ncpus;
+	root->cg_children = vm_ndomains;
+	root->cg_level = CG_SHARE_NONE;
+	root->cg_flags = 0;
+
+	/*
+	 * Redundant layers will be collapsed by the caller so we don't need a
+	 * special case for a single domain.
+	 */
+	for (i = 0; i < vm_ndomains; i++, dom++) {
+		dom->cg_parent = root;
+		dom->cg_child = NULL;
+		CPU_COPY(&cpuset_domain[i], &dom->cg_mask);
+		dom->cg_count = CPU_COUNT(&dom->cg_mask);
+		dom->cg_children = 0;
+		dom->cg_level = CG_SHARE_L3;
+		dom->cg_flags = 0;
+	}
 
-	return (smp_topo_none());
+	return (root);
 }
 
 /* Determine if we running MP machine */