linux-kernel - [PATCH 01/16] mm/migration: remove unneeded local variable mapping

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Date:   Fri, 4 Mar 2022 17:33:54 +0800
From:   Miaohe Lin <linmiaohe@...wei.com>
To:     <akpm@...ux-foundation.org>
CC:     <mike.kravetz@...cle.com>, <shy828301@...il.com>,
        <willy@...radead.org>, <ying.huang@...el.com>, <ziy@...dia.com>,
        <minchan@...nel.org>, <apopple@...dia.com>,
        <ave.hansen@...ux.intel.com>, <o451686892@...il.com>,
        <almasrymina@...gle.com>, <jhubbard@...dia.com>,
        <rcampbell@...dia.com>, <peterx@...hat.com>,
        <naoya.horiguchi@....com>, <mhocko@...e.com>, <riel@...hat.com>,
        <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
        <linmiaohe@...wei.com>
Subject: [PATCH 01/16] mm/migration: remove unneeded local variable mapping_locked

When mapping_locked is true, TTU_RMAP_LOCKED is always set to ttu. We can
check ttu instead so mapping_locked can be removed. And ttu is either 0
or TTU_RMAP_LOCKED now. Change '|=' to '=' to reflect this.

Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
---
 mm/migrate.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 42e3a944f35c..50bc62d85eaf 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1230,7 +1230,6 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
 		goto put_anon;
 
 	if (page_mapped(hpage)) {
-		bool mapping_locked = false;
 		enum ttu_flags ttu = 0;
 
 		if (!PageAnon(hpage)) {
@@ -1244,14 +1243,13 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
 			if (unlikely(!mapping))
 				goto unlock_put_anon;
 
-			mapping_locked = true;
-			ttu |= TTU_RMAP_LOCKED;
+			ttu = TTU_RMAP_LOCKED;
 		}
 
 		try_to_migrate(src, ttu);
 		page_was_mapped = 1;
 
-		if (mapping_locked)
+		if (ttu & TTU_RMAP_LOCKED)
 			i_mmap_unlock_write(mapping);
 	}
 
-- 
2.23.0