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Commit 68fd111e authored by David Rientjes's avatar David Rientjes Committed by H. Peter Anvin
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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: default avatarDavid Rientjes <rientjes@google.com>
LKML-Reference: <alpine.DEB.2.00.1002151342230.26927@chino.kir.corp.google.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 0271f910

arch/x86/mm/numa_64.c

+1 −1
Original line number Diff line number Diff line
@@ -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;