linux-kernel - [PATCH 4/6] mm/huge_memory.c: remove redundant PageCompound() check

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Message-ID: <20210313103225.16607-6-linmiaohe@huawei.com>
Date:   Sat, 13 Mar 2021 05:32:23 -0500
From:   Miaohe Lin <linmiaohe@...wei.com>
To:     <akpm@...ux-foundation.org>
CC:     <ziy@...dia.com>, <willy@...radead.org>,
        <william.kucharski@...cle.com>, <vbabka@...e.cz>,
        <richard.weiyang@...ux.alibaba.com>, <peterx@...hat.com>,
        <anshuman.khandual@....com>, <thomas_os@...pmail.org>,
        <rcampbell@...dia.com>, <aneesh.kumar@...ux.ibm.com>,
        <yang.shi@...ux.alibaba.com>, <linux-kernel@...r.kernel.org>,
        <linux-mm@...ck.org>, <linmiaohe@...wei.com>
Subject: [PATCH 4/6] mm/huge_memory.c: remove redundant PageCompound() check

The !PageCompound() check limits the page must be head or tail while
!PageHead() further limits it to page head only. So !PageHead() check
is equivalent here.

Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
---
 mm/huge_memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 26f91bf15613..c00205e7c548 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1291,7 +1291,7 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
 	}
 
 	page = pmd_page(orig_pmd);
-	VM_BUG_ON_PAGE(!PageCompound(page) || !PageHead(page), page);
+	VM_BUG_ON_PAGE(!PageHead(page), page);
 
 	/* Lock page for reuse_swap_page() */
 	if (!trylock_page(page)) {
-- 
2.19.1