Re: [PATCH v5 02/11] mm/mempolicy: introduce MPOL_WEIGHTED_INTERLEAVE for weighted interleaving

On Tue, Dec 26, 2023 at 02:01:57AM -0500, Gregory Price wrote:

On Wed, Dec 27, 2023 at 04:32:37PM +0800, Huang, Ying wrote:

quoted

Gregory Price [off-list ref] writes:

Barrier is to stabilize nodemask on the stack, but yes i'll carry the
comment from interleave_nid into this barrier as well.

quoted

quoted

+
+	/* first ensure we have a valid nodemask */
+	nid = first_node(nodemask);
+	if (nid == MAX_NUMNODES)
+		return nid;

It appears that this isn't necessary, because we can check whether
weight_total == 0 after the next loop.

fair, will snip.

Follow up - this is only possible if the nodemask is invalid / has no
nodes, so it's better to check for this explicitly.  If nodemask is
valid, then it's not possible to have a weight_total of 0, because
weights cannot be 0.

~Gregory