x86-64: Combine SRAT regions when possible
... i.e. when the hole between two regions isn't occupied by memory on
another node. This reduces the memory->node table size, thus reducing
cache footprint of lookups, which got increased significantly some
time ago, and things go back to how they were before that change on
the systems I looked at.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <4BCF3230020000780003B3CA@vpn.id2.novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/mm/srat_64.c b/arch/x86/mm/srat_64.c
index 28c6876..3ebe651 100644
--- a/arch/x86/mm/srat_64.c
+++ b/arch/x86/mm/srat_64.c
@@ -363,6 +363,54 @@
for (i = 0; i < MAX_NUMNODES; i++)
cutoff_node(i, start, end);
+ /*
+ * Join together blocks on the same node, holes between
+ * which don't overlap with memory on other nodes.
+ */
+ for (i = 0; i < num_node_memblks; ++i) {
+ int j, k;
+
+ for (j = i + 1; j < num_node_memblks; ++j) {
+ unsigned long start, end;
+
+ if (memblk_nodeid[i] != memblk_nodeid[j])
+ continue;
+ start = min(node_memblk_range[i].end,
+ node_memblk_range[j].end);
+ end = max(node_memblk_range[i].start,
+ node_memblk_range[j].start);
+ for (k = 0; k < num_node_memblks; ++k) {
+ if (memblk_nodeid[i] == memblk_nodeid[k])
+ continue;
+ if (start < node_memblk_range[k].end &&
+ end > node_memblk_range[k].start)
+ break;
+ }
+ if (k < num_node_memblks)
+ continue;
+ start = min(node_memblk_range[i].start,
+ node_memblk_range[j].start);
+ end = max(node_memblk_range[i].end,
+ node_memblk_range[j].end);
+ printk(KERN_INFO "SRAT: Node %d "
+ "[%Lx,%Lx) + [%Lx,%Lx) -> [%lx,%lx)\n",
+ memblk_nodeid[i],
+ node_memblk_range[i].start,
+ node_memblk_range[i].end,
+ node_memblk_range[j].start,
+ node_memblk_range[j].end,
+ start, end);
+ node_memblk_range[i].start = start;
+ node_memblk_range[i].end = end;
+ k = --num_node_memblks - j;
+ memmove(memblk_nodeid + j, memblk_nodeid + j+1,
+ k * sizeof(*memblk_nodeid));
+ memmove(node_memblk_range + j, node_memblk_range + j+1,
+ k * sizeof(*node_memblk_range));
+ --j;
+ }
+ }
+
memnode_shift = compute_hash_shift(node_memblk_range, num_node_memblks,
memblk_nodeid);
if (memnode_shift < 0) {
