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Commit fee83b3a authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
Browse files

mm/mempolicy.c:offset_il_node() document and clarify 



This code was pretty obscure and was relying upon obscure side-effects
of next_node(-1, ...) and was relying upon NUMA_NO_NODE being equal to
-1.

Clean that all up and document the function's intent.

Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 54f18d35

mm/mempolicy.c

+11 −9
Original line number Original line Diff line number Diff line
@@ -1758,23 +1758,25 @@ unsigned int mempolicy_slab_node(void) 
	}

	}

}

}





/* Do static interleaving for a VMA with known offset. */

/*

 * Do static interleaving for a VMA with known offset @n.  Returns the n'th

 * node in pol->v.nodes (starting from n=0), wrapping around if n exceeds the

 * number of present nodes.

 */

static unsigned offset_il_node(struct mempolicy *pol,

static unsigned offset_il_node(struct mempolicy *pol,

		struct vm_area_struct *vma, unsigned long off)

			       struct vm_area_struct *vma, unsigned long n)

{

{

	unsigned nnodes = nodes_weight(pol->v.nodes);

	unsigned nnodes = nodes_weight(pol->v.nodes);

	unsigned target;

	unsigned target;

	int c;

	int i;

	int nid = NUMA_NO_NODE;

	int nid;





	if (!nnodes)

	if (!nnodes)

		return numa_node_id();

		return numa_node_id();

	target = (unsigned int)off % nnodes;

	target = (unsigned int)n % nnodes;

	c = 0;

	nid = first_node(pol->v.nodes);

	do {

	for (i = 0; i < target; i++)

		nid = next_node(nid, pol->v.nodes);

		nid = next_node(nid, pol->v.nodes);

		c++;

	} while (c <= target);

	return nid;

	return nid;

}

}