sparc64: Fix numa distance values
Orabug: 21896119
Use machine descriptor (MD) to get node latency
values instead of just using default values.
Testing:
On an T5-8 system with:
- total nodes = 8
- self latencies = 0x26d18
- latency to other nodes = 0x3a598
=> latency ratio = ~1.5
output of numactl --hardware
- before fix:
node distances:
node 0 1 2 3 4 5 6 7
0: 10 20 20 20 20 20 20 20
1: 20 10 20 20 20 20 20 20
2: 20 20 10 20 20 20 20 20
3: 20 20 20 10 20 20 20 20
4: 20 20 20 20 10 20 20 20
5: 20 20 20 20 20 10 20 20
6: 20 20 20 20 20 20 10 20
7: 20 20 20 20 20 20 20 10
- after fix:
node distances:
node 0 1 2 3 4 5 6 7
0: 10 15 15 15 15 15 15 15
1: 15 10 15 15 15 15 15 15
2: 15 15 10 15 15 15 15 15
3: 15 15 15 10 15 15 15 15
4: 15 15 15 15 10 15 15 15
5: 15 15 15 15 15 10 15 15
6: 15 15 15 15 15 15 10 15
7: 15 15 15 15 15 15 15 10
Signed-off-by: Nitin Gupta <nitin.m.gupta@oracle.com>
Reviewed-by: Chris Hyser <chris.hyser@oracle.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/include/asm/topology_64.h b/arch/sparc/include/asm/topology_64.h
index 01d1704..bec481a 100644
--- a/arch/sparc/include/asm/topology_64.h
+++ b/arch/sparc/include/asm/topology_64.h
@@ -31,6 +31,9 @@
cpu_all_mask : \
cpumask_of_node(pcibus_to_node(bus)))
+int __node_distance(int, int);
+#define node_distance(a, b) __node_distance(a, b)
+
#else /* CONFIG_NUMA */
#include <asm-generic/topology.h>
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 4ac88b7..3025bd5 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -93,6 +93,8 @@
static struct linux_prom64_registers pavail[MAX_BANKS];
static int pavail_ents;
+u64 numa_latency[MAX_NUMNODES][MAX_NUMNODES];
+
static int cmp_p64(const void *a, const void *b)
{
const struct linux_prom64_registers *x = a, *y = b;
@@ -1157,6 +1159,48 @@
return NULL;
}
+int __node_distance(int from, int to)
+{
+ if ((from >= MAX_NUMNODES) || (to >= MAX_NUMNODES)) {
+ pr_warn("Returning default NUMA distance value for %d->%d\n",
+ from, to);
+ return (from == to) ? LOCAL_DISTANCE : REMOTE_DISTANCE;
+ }
+ return numa_latency[from][to];
+}
+
+static int find_best_numa_node_for_mlgroup(struct mdesc_mlgroup *grp)
+{
+ int i;
+
+ for (i = 0; i < MAX_NUMNODES; i++) {
+ struct node_mem_mask *n = &node_masks[i];
+
+ if ((grp->mask == n->mask) && (grp->match == n->val))
+ break;
+ }
+ return i;
+}
+
+static void find_numa_latencies_for_group(struct mdesc_handle *md, u64 grp,
+ int index)
+{
+ u64 arc;
+
+ mdesc_for_each_arc(arc, md, grp, MDESC_ARC_TYPE_FWD) {
+ int tnode;
+ u64 target = mdesc_arc_target(md, arc);
+ struct mdesc_mlgroup *m = find_mlgroup(target);
+
+ if (!m)
+ continue;
+ tnode = find_best_numa_node_for_mlgroup(m);
+ if (tnode == MAX_NUMNODES)
+ continue;
+ numa_latency[index][tnode] = m->latency;
+ }
+}
+
static int __init numa_attach_mlgroup(struct mdesc_handle *md, u64 grp,
int index)
{
@@ -1220,9 +1264,16 @@
static int __init numa_parse_mdesc(void)
{
struct mdesc_handle *md = mdesc_grab();
- int i, err, count;
+ int i, j, err, count;
u64 node;
+ /* Some sane defaults for numa latency values */
+ for (i = 0; i < MAX_NUMNODES; i++) {
+ for (j = 0; j < MAX_NUMNODES; j++)
+ numa_latency[i][j] = (i == j) ?
+ LOCAL_DISTANCE : REMOTE_DISTANCE;
+ }
+
node = mdesc_node_by_name(md, MDESC_NODE_NULL, "latency-groups");
if (node == MDESC_NODE_NULL) {
mdesc_release(md);
@@ -1245,6 +1296,23 @@
count++;
}
+ count = 0;
+ mdesc_for_each_node_by_name(md, node, "group") {
+ find_numa_latencies_for_group(md, node, count);
+ count++;
+ }
+
+ /* Normalize numa latency matrix according to ACPI SLIT spec. */
+ for (i = 0; i < MAX_NUMNODES; i++) {
+ u64 self_latency = numa_latency[i][i];
+
+ for (j = 0; j < MAX_NUMNODES; j++) {
+ numa_latency[i][j] =
+ (numa_latency[i][j] * LOCAL_DISTANCE) /
+ self_latency;
+ }
+ }
+
add_node_ranges();
for (i = 0; i < num_node_masks; i++) {