Commit 14694d73 authored by David Rientjes's avatar David Rientjes Committed by Andi Kleen
Browse files

[PATCH] x86-64: split remaining fake nodes equally 



Extends the numa=fake x86_64 command-line option to split the remaining
system memory into equal-sized nodes.

For example:
numa=fake=2*512,4*	gives two 512M nodes and the remaining system
			memory is split into four approximately equal
			chunks.

This is beneficial for systems where the exact size of RAM is unknown or not
necessarily relevant, but the granularity with which nodes shall be allocated
is known.

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 8b8ca80e

Documentation/x86_64/boot-options.txt

+3 −1
Original line number Diff line number Diff line
@@ -155,7 +155,9 @@ NUMA 
		depending on the sizes and coefficients listed.  For example:

			numa=fake=2*512,1024,4*256

		gives two 512M nodes, a 1024M node, and four 256M nodes.  The

		remaining system RAM is allocated to an additional node.

		remaining system RAM is allocated to an additional node.  If

		the last character of CMDLINE is a *, the remaining system RAM

		is instead divided up equally among its coefficient.



  numa=hotadd=percent

		Only allow hotadd memory to preallocate page structures upto

arch/x86_64/mm/numa.c

+18 −4
Original line number Diff line number Diff line
@@ -418,12 +418,26 @@ static int __init numa_emulation(unsigned long start_pfn, unsigned long end_pfn) 
done:

	if (!num_nodes)

		return -1;

	/* Fill remainder of system RAM with a final node, if appropriate. */

	/* Fill remainder of system RAM, if appropriate. */

	if (addr < max_addr) {

		setup_node_range(num_nodes, nodes, &addr, max_addr - addr,

				 max_addr);

		switch (*(cmdline - 1)) {

		case '*':

			/* Split remaining nodes into coeff chunks */

			if (coeff <= 0)

				break;

			num_nodes += split_nodes_equally(nodes, &addr, max_addr,

							 num_nodes, coeff);

			break;

		case ',':

			/* Do not allocate remaining system RAM */

			break;

		default:

			/* Give one final node */

			setup_node_range(num_nodes, nodes, &addr,

					 max_addr - addr, max_addr);

			num_nodes++;

		}

	}

out:

	memnode_shift = compute_hash_shift(nodes, num_nodes);

	if (memnode_shift < 0) {

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