[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: David Rientjes <rientjes@google.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 18 insertions, 4 deletions

diff --git a/arch/x86_64/mm/numa.c b/arch/x86_64/mm/numa.c
index c55936bc6be6..0ae2d9d5d7ea 100644
--- a/arch/x86_64/mm/numa.c
+++ b/arch/x86_64/mm/numa.c
@@ -418,11 +418,25 @@ 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);
-                num_nodes++;
+                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);