[tip:x86/numa] x86, numa: Fix numa emulation calculation of big nodes

[tip-bot for David Rientjes]

Commit-ID:  68fd111e02b979876359c7b471a8bcbca0628b75
Gitweb:     http://git.kernel.org/tip/68fd111e02b979876359c7b471a8bcbca0628b75
Author:     David Rientjes <rientjes@xxxxxxxxxx>
AuthorDate: Mon, 15 Feb 2010 13:43:25 -0800
Committer:  H. Peter Anvin <hpa@xxxxxxxxx>
CommitDate: Mon, 15 Feb 2010 14:34:04 -0800

x86, numa: Fix numa emulation calculation of big nodes

numa=fake=N uses split_nodes_interleave() to partition the system into N
fake nodes.  Each node size must have be a multiple of
FAKE_NODE_MIN_SIZE, otherwise it is possible to get strange alignments.
Because of this, the remaining memory from each node when rounded to
FAKE_NODE_MIN_SIZE is consolidated into a number of "big nodes" that are
bigger than the rest.

The calculation of the number of big nodes is incorrect since it is using
a logical AND operator when it should be multiplying the rounded-off
portion of each node with N.

Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
LKML-Reference: <alpine.DEB.2.00.1002151342230.26927@xxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx>
---
 arch/x86/mm/numa_64.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c
index 83bbc70..2ecbe0c 100644
--- a/arch/x86/mm/numa_64.c
+++ b/arch/x86/mm/numa_64.c
@@ -427,7 +427,7 @@ static int __init split_nodes_interleave(u64 addr, u64 max_addr,
 	 * Calculate the number of big nodes that can be allocated as a result
 	 * of consolidating the remainder.
 	 */
-	big = ((size & ~FAKE_NODE_MIN_HASH_MASK) & nr_nodes) /
+	big = ((size & ~FAKE_NODE_MIN_HASH_MASK) * nr_nodes) /
 		FAKE_NODE_MIN_SIZE;
 
 	size &= FAKE_NODE_MIN_HASH_MASK;
--
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