Commit 2e618786 authored by Jan Beulich's avatar Jan Beulich Committed by H. Peter Anvin
Browse files

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: default avatarJan Beulich <jbeulich@novell.com>
LKML-Reference: <4BCF3230020000780003B3CA@vpn.id2.novell.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 1d16b0f2

arch/x86/mm/srat_64.c

+48 −0
Original line number Diff line number Diff line
@@ -363,6 +363,54 @@ int __init acpi_scan_nodes(unsigned long start, unsigned long end) 
	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) {

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