[PATCH 1/2] mm: refactor find_next_best_node to find_next_best_node_in
From: Gregory Price <gourry@gourry.net>
Date: 2026-09-02 21:59:02
Also in:
lkml
Subsystem:
memory management, memory management - core, memory management - misc, memory management - page allocator, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Vlastimil Babka, Linus Torvalds
find_next_best_node() picks the next-closest node for a fallback list from the full N_MEMORY set. Refactor it into find_next_best_node_in(), which takes an explicit candidates nodemask. This enables building fallback lists with non-N_MEMORY candidates. No functional change: every caller still selects from N_MEMORY. Signed-off-by: Gregory Price <gourry@gourry.net> --- mm/internal.h | 6 ++++-- mm/memory-tiers.c | 7 ++++--- mm/page_alloc.c | 13 ++++++++----- 3 files changed, 16 insertions(+), 10 deletions(-)
diff --git a/mm/internal.h b/mm/internal.h
index e16f1250b25c8..18d041ff5c52c 100644
--- a/mm/internal.h
+++ b/mm/internal.h@@ -1130,7 +1130,8 @@ extern int node_reclaim_mode; extern unsigned long node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned int order); -extern int find_next_best_node(int node, nodemask_t *used_node_mask); +extern int find_next_best_node_in(int node, nodemask_t *used_node_mask, + const nodemask_t *candidates); #else #define node_reclaim_mode 0
@@ -1139,7 +1140,8 @@ static inline unsigned long node_reclaim(struct pglist_data *pgdat, { return 0; } -static inline int find_next_best_node(int node, nodemask_t *used_node_mask) +static inline int find_next_best_node_in(int node, nodemask_t *used_node_mask, + const nodemask_t *candidates) { return NUMA_NO_NODE; }
diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
index 54851d8a195b0..25e121851b586 100644
--- a/mm/memory-tiers.c
+++ b/mm/memory-tiers.c@@ -370,7 +370,7 @@ int next_demotion_node(int node, const nodemask_t *allowed_mask) * closest demotion target. */ nodes_complement(mask, *allowed_mask); - return find_next_best_node(node, &mask); + return find_next_best_node_in(node, &mask, &node_states[N_MEMORY]); } static void disable_all_demotion_targets(void)
@@ -450,7 +450,7 @@ static void establish_demotion_targets(void) memtier = list_next_entry(memtier, list); tier_nodes = get_memtier_nodemask(memtier); /* - * find_next_best_node, use 'used' nodemask as a skip list. + * find_next_best_node_in, use 'used' nodemask as a skip list. * Add all memory nodes except the selected memory tier * nodelist to skip list so that we find the best node from the * memtier nodelist.
@@ -463,7 +463,8 @@ static void establish_demotion_targets(void) * in the preferred mask when allocating pages during demotion. */ do { - target = find_next_best_node(node, &tier_nodes); + target = find_next_best_node_in(node, &tier_nodes, + &node_states[N_MEMORY]); if (target == NUMA_NO_NODE) break;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c4dc61ec663ee..4dde1cbe2fd43 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c@@ -5779,9 +5779,10 @@ static int numa_zonelist_order_handler(const struct ctl_table *table, int write, static int node_load[MAX_NUMNODES]; /** - * find_next_best_node - find the next node that should appear in a given node's fallback list + * find_next_best_node_in - find the next node that should appear in a given node's fallback list * @node: node whose fallback list we're appending * @used_node_mask: nodemask_t of already used nodes + * @candidates: nodemask_t of nodes eligible for selection * * We use a number of factors to determine which is the next node that should * appear on a given node's fallback list. The node should not have appeared
@@ -5793,7 +5794,8 @@ static int node_load[MAX_NUMNODES]; * * Return: node id of the found node or %NUMA_NO_NODE if no node is found. */ -int find_next_best_node(int node, nodemask_t *used_node_mask) +int find_next_best_node_in(int node, nodemask_t *used_node_mask, + const nodemask_t *candidates) { int n, val; int min_val = INT_MAX;
@@ -5803,12 +5805,12 @@ int find_next_best_node(int node, nodemask_t *used_node_mask) * Use the local node if we haven't already, but for memoryless local * node, we should skip it and fall back to other nodes. */ - if (!node_isset(node, *used_node_mask) && node_state(node, N_MEMORY)) { + if (!node_isset(node, *used_node_mask) && node_isset(node, *candidates)) { node_set(node, *used_node_mask); return node; } - for_each_node_state(n, N_MEMORY) { + for_each_node_mask(n, *candidates) { /* Don't want a node to appear more than once */ if (node_isset(n, *used_node_mask))
@@ -5893,7 +5895,8 @@ static void build_zonelists(pg_data_t *pgdat) prev_node = local_node; memset(node_order, 0, sizeof(node_order)); - while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { + while ((node = find_next_best_node_in(local_node, &used_mask, + &node_states[N_MEMORY])) >= 0) { /* * We don't want to pressure a particular node. * So adding penalty to the first node in same
--
2.53.0-Meta