[PATCH 3/3] mm/page_alloc: remove pcpu_spin_* wrappers

From: Vlastimil Babka

Date: Fri Feb 27 2026 - 12:10:47 EST


We only ever use pcpu_spin_trylock()/unlock() with struct per_cpu_pages
so refactor the helpers to remove the generic layer.

No functional change intended.

Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@xxxxxxxxxx>
---
mm/page_alloc.c | 24 +++++++++---------------
1 file changed, 9 insertions(+), 15 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8e5b30adfe40..b1007afa9492 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -112,35 +112,29 @@ static DEFINE_MUTEX(pcp_batch_high_lock);
#endif

/*
- * Generic helper to lookup and a per-cpu variable with an embedded spinlock.
- * Return value should be used with equivalent unlock helper.
+ * A helper to lookup and trylock pcp with embedded spinlock.
+ * The return value should be used with the unlock helper.
+ * NULL return value means the trylock failed.
*/
-#define pcpu_spin_trylock(type, member, ptr) \
+#ifdef CONFIG_SMP
+#define pcp_spin_trylock(ptr) \
({ \
- type *_ret; \
+ struct per_cpu_pages *_ret; \
pcpu_task_pin(); \
_ret = this_cpu_ptr(ptr); \
- if (!spin_trylock(&_ret->member)) { \
+ if (!spin_trylock(&_ret->lock)) { \
pcpu_task_unpin(); \
_ret = NULL; \
} \
_ret; \
})

-#define pcpu_spin_unlock(member, ptr) \
+#define pcp_spin_unlock(ptr) \
({ \
- spin_unlock(&ptr->member); \
+ spin_unlock(&ptr->lock); \
pcpu_task_unpin(); \
})

-/* struct per_cpu_pages specific helpers.*/
-#ifdef CONFIG_SMP
-#define pcp_spin_trylock(ptr) \
- pcpu_spin_trylock(struct per_cpu_pages, lock, ptr)
-
-#define pcp_spin_unlock(ptr) \
- pcpu_spin_unlock(lock, ptr)
-
/*
* On CONFIG_SMP=n the UP implementation of spin_trylock() never fails and thus
* is not compatible with our locking scheme. However we do not need pcp for

--
2.53.0