From 386781df63cb4d847f21dc9452d251a6d63d89b2 Mon Sep 17 00:00:00 2001
From: Yury Norov <ynorov@nvidia.com>
Date: Wed, 14 Jan 2026 12:22:14 -0500
Subject: [PATCH] mm: use nodes_and() return value to simplify client code
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establish_demotion_targets() and kernel_migrate_pages() call node_empty()
immediately after calling nodes_and().  Now that nodes_and() return false
if nodemask is empty, drop the latter.

Link: https://lkml.kernel.org/r/20260114172217.861204-3-ynorov@nvidia.com
Signed-off-by: Yury Norov <ynorov@nvidia.com>
Reviewed-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mathew Brost <matthew.brost@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/memory-tiers.c | 3 +--
 mm/mempolicy.c    | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
index 20aab9c19c5e5..7ec4427765741 100644
--- a/mm/memory-tiers.c
+++ b/mm/memory-tiers.c
@@ -475,8 +475,7 @@ static void establish_demotion_targets(void)
 	 */
 	list_for_each_entry_reverse(memtier, &memory_tiers, list) {
 		tier_nodes = get_memtier_nodemask(memtier);
-		nodes_and(tier_nodes, node_states[N_CPU], tier_nodes);
-		if (!nodes_empty(tier_nodes)) {
+		if (nodes_and(tier_nodes, node_states[N_CPU], tier_nodes)) {
 			/*
 			 * abstract distance below the max value of this memtier
 			 * is considered toptier.
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 76da504257123..dbd48502ac240 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1909,8 +1909,7 @@ static int kernel_migrate_pages(pid_t pid, unsigned long maxnode,
 	}
 
 	task_nodes = cpuset_mems_allowed(current);
-	nodes_and(*new, *new, task_nodes);
-	if (nodes_empty(*new))
+	if (!nodes_and(*new, *new, task_nodes))
 		goto out_put;
 
 	err = security_task_movememory(task);
-- 
2.47.3