[062/192] mm/z3fold: remove magic number in z3fold_create_pool()

Commit Message

Andrew Morton July 1, 2021, 1:50 a.m. UTC

From: Miaohe Lin <[e-mail]>
Subject: mm/z3fold: remove magic number in z3fold_create_pool()

It's meaningless to pass a magic number 2 to __alloc_percpu() as there is
a minimum alignment size of PCPU_MIN_ALLOC_SIZE (> 2) in it.  Also there
is no special alignment requirement for unbuddied.  So we could replace
this magic number with nature alignment, i.e.  __alignof__(struct
list_head), to improve readability.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Miaohe Lin <[e-mail]>
Reviewed-by: Vitaly Wool <[e-mail]>
Cc: Hillf Danton <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/z3fold.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Patch

--- a/mm/z3fold.c~mm-z3fold-remove-magic-number-in-z3fold_create_pool
+++ a/mm/z3fold.c
@@ -998,7 +998,8 @@  static struct z3fold_pool *z3fold_create
 		goto out_c;
 	spin_lock_init(&pool->lock);
 	spin_lock_init(&pool->stale_lock);
-	pool->unbuddied = __alloc_percpu(sizeof(struct list_head)*NCHUNKS, 2);
+	pool->unbuddied = __alloc_percpu(sizeof(struct list_head) * NCHUNKS,
+					 __alignof__(struct list_head));
 	if (!pool->unbuddied)
 		goto out_pool;
 	for_each_possible_cpu(cpu) {