[PATCH] x86-64: fixed size remaining fake nodes

Extends the numa=fake x86_64 command-line option to split the remaining system
memory into nodes of fixed size.  Any leftover memory is allocated to a final
node unless the command-line ends with a comma.

For example:
  numa=fake=2*512,*128	gives two 512M nodes and the remaining system
			memory is split into nodes of 128M each.

This is beneficial for systems where the exact size of RAM is unknown or not
necessarily relevant, but the size of the remaining nodes to be allocated is
known based on their capacity for resource management.

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, 9 insertions, 5 deletions

diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt
index 12a9aacecaae..6177d881983f 100644
--- a/Documentation/x86_64/boot-options.txt
+++ b/Documentation/x86_64/boot-options.txt
@@ -153,11 +153,15 @@ NUMA
                 If a number, fakes CMDLINE nodes and ignores NUMA setup of the
                 actual machine.  Otherwise, system memory is configured
                 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.  If
-                the last character of CMDLINE is a *, the remaining system RAM
-                is instead divided up equally among its coefficient.
+                        numa=fake=2*512,1024,4*256,*128
+                gives two 512M nodes, a 1024M node, four 256M nodes, and the
+                rest split into 128M chunks.  If the last character of CMDLINE
+                is a *, the remaining memory is divided up equally among its
+                coefficient:
+                        numa=fake=2*512,2*
+                gives two 512M nodes and the rest split into two nodes.
+                Otherwise, the remaining system RAM is allocated to an
+                additional node.
 
   numa=hotadd=percent
                 Only allow hotadd memory to preallocate page structures upto