From: Songtang Liu <liusongtang@bytedance.com>
Date: Wed, 2 Apr 2025 07:41:16 +0000 (-0400)
Subject: mm: page_alloc: remove redundant READ_ONCE
X-Git-Tag: v6.16-rc1~92^2~262
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cd348c5e6af3b4220eb37a08fdaf9c924a2e1c19;p=thirdparty%2Fkernel%2Fstable.git

mm: page_alloc: remove redundant READ_ONCE

In the current code, batch is a local variable, and it cannot be
concurrently modified.  It's unnecessary to use READ_ONCE here, so remove
it.

Link: https://lkml.kernel.org/r/CAA=HWd1kn01ym8YuVFuAqK2Ggq3itEGkqX8T6eCXs_C7tiv-Jw@mail.gmail.com
Fixes: 51a755c56dc0 ("mm: tune PCP high automatically")
Signed-off-by: Songtang Liu <liusongtang@bytedance.com>
Reviewed-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Huang Ying <ying.huang@linux.alibaba.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8258349e49acb..1ee0e8265888b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2675,7 +2675,7 @@ static void free_frozen_page_commit(struct zone *zone,
 		free_high = (pcp->free_count >= batch &&
 			     (pcp->flags & PCPF_PREV_FREE_HIGH_ORDER) &&
 			     (!(pcp->flags & PCPF_FREE_HIGH_BATCH) ||
-			      pcp->count >= READ_ONCE(batch)));
+			      pcp->count >= batch));
 		pcp->flags |= PCPF_PREV_FREE_HIGH_ORDER;
 	} else if (pcp->flags & PCPF_PREV_FREE_HIGH_ORDER) {
 		pcp->flags &= ~PCPF_PREV_FREE_HIGH_ORDER;