Commit dc9e0a93 authored Mar 15, 2018 by Dan Williams

acpi, numa: fix pxm to online numa node associations



Commit 99759869 "acpi: Add acpi_map_pxm_to_online_node()" added
support for mapping a given proximity to its nearest, by SLIT distance,
online node. However, it sometimes returns unexpected results due to the
fact that it switches from comparing the PXM node to the last node that
was closer than the current max.

    for_each_online_node(n) {
            dist = node_distance(node, n);
            if (dist < min_dist) {
                    min_dist = dist;
                    node = n;	<---- from this point we're using the
				      wrong node for node_distance()


Fixes: 99759869 ("acpi: Add acpi_map_pxm_to_online_node()")
Cc: <stable@vger.kernel.org>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com&gt;>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

parent a7e6c701

drivers/acpi/numa.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -103,25 +103,27 @@ int acpi_map_pxm_to_node(int pxm)
		*/
		int acpi_map_pxm_to_online_node(int pxm)
		{
		int node, n, dist, min_dist;
		int node, min_node;

		node = acpi_map_pxm_to_node(pxm);

		if (node == NUMA_NO_NODE)
		node = 0;

		min_node = node;
		if (!node_online(node)) {
		min_dist = INT_MAX;
		int min_dist = INT_MAX, dist, n;

		for_each_online_node(n) {
		dist = node_distance(node, n);
		if (dist < min_dist) {
		min_dist = dist;
		node = n;
		min_node = n;
		}
		}
		}

		return node;
		return min_node;
		}
		EXPORT_SYMBOL(acpi_map_pxm_to_online_node);

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