powerpc/numa: Limit possible nodes to within num_possible_nodes (dbce4562) · Commits · 戴 / test

MAX_NUMNODES is a theoretical maximum number of nodes thats is supported by the kernel. Device tree properties exposes the number of possible nodes on the current platform. The kernel would detected this and would use it for most of its resource allocations. If the platform now increases the nodes to over what was already exposed, then it may lead to inconsistencies. Hence limit it to the already exposed nodes. Suggested-by:

Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by:

Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by:

Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724105809.24733-1-srikar@linux.vnet.ibm.com

arch/powerpc/mm/numa.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -221,7 +221,8 @@ static void initialize_distance_lookup_table(int nid,
		}
		}

		/* Returns nid in the range [0..MAX_NUMNODES-1], or -1 if no useful numa
		/*
		* Returns nid in the range [0..nr_node_ids], or -1 if no useful NUMA
		* info is found.
		*/
		static int associativity_to_nid(const __be32 *associativity)
		@@ -235,7 +236,7 @@ static int associativity_to_nid(const __be32 *associativity)
		nid = of_read_number(&associativity[min_common_depth], 1);

		/* POWER4 LPAR uses 0xffff as invalid node */
		if (nid == 0xffff \|\| nid >= MAX_NUMNODES)
		if (nid == 0xffff \|\| nid >= nr_node_ids)
		nid = NUMA_NO_NODE;

		if (nid > 0 &&
		@@ -448,7 +449,7 @@ static int of_drconf_to_nid_single(struct drmem_lmb *lmb)
		index = lmb->aa_index * aa.array_sz + min_common_depth - 1;
		nid = of_read_number(&aa.arrays[index], 1);

		if (nid == 0xffff \|\| nid >= MAX_NUMNODES)
		if (nid == 0xffff \|\| nid >= nr_node_ids)
		nid = default_nid;

		if (nid > 0) {

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