[PATCH 11/17] lib/nodemask: add num_node_state_eq()

From: Yury Norov <yury.norov@gmail.com>
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Subject: [PATCH 11/17] lib/nodemask: add num_node_state_eq()
Date: Sat, 18 Dec 2021 13:20:07 -0800	[thread overview]
Message-ID: <20211218212014.1315894-12-yury.norov@gmail.com> (raw)
In-Reply-To: <20211218212014.1315894-1-yury.norov@gmail.com>

Kernel code calls num_node_state() to compare number of nodes with a given
number. The underlying code calls bitmap_weight(), and we can do it more
efficiently with num_node_state_eq because conditional nodes_weight may
stop traversing the nodemask earlier, as soon as condition is met.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
 include/linux/nodemask.h | 5 +++++
 mm/page_alloc.c          | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index 197598e075e9..c5014dbf3cce 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -466,6 +466,11 @@ static inline int num_node_state(enum node_states state)
 	return nodes_weight(node_states[state]);
 }
 
+static inline int num_node_state_eq(enum node_states state, int num)
+{
+	return nodes_weight_eq(node_states[state], num);
+}
+
 #define for_each_node_state(__node, __state) \
 	for_each_node_mask((__node), node_states[__state])
 
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index edfd6c81af82..71f5652828b8 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8323,7 +8323,7 @@ void __init page_alloc_init(void)
 	int ret;
 
 #ifdef CONFIG_NUMA
-	if (num_node_state(N_MEMORY) == 1)
+	if (num_node_state_eq(N_MEMORY, 1))
 		hashdist = 0;
 #endif
 
-- 
2.30.2

