From c43bc03d0a872dcfcaaf1689c4f6140f9d3cb867 Mon Sep 17 00:00:00 2001
From: Xianting Tian <tian.xianting@h3c.com>
Date: Tue, 13 Oct 2020 16:54:42 -0700
Subject: mm/memory-failure: do pgoff calculation before for_each_process()

There is no need to calculate pgoff in each loop of for_each_process(), so
move it to the place before for_each_process(), which can save some CPU
cycles.

Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Link: http://lkml.kernel.org/r/20200818082647.34322-1-tian.xianting@h3c.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/memory-failure.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index a1e73943445e..24c28f80628d 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -484,11 +484,12 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill,
 	struct vm_area_struct *vma;
 	struct task_struct *tsk;
 	struct address_space *mapping = page->mapping;
+	pgoff_t pgoff;
 
 	i_mmap_lock_read(mapping);
 	read_lock(&tasklist_lock);
+	pgoff = page_to_pgoff(page);
 	for_each_process(tsk) {
-		pgoff_t pgoff = page_to_pgoff(page);
 		struct task_struct *t = task_early_kill(tsk, force_early);
 
 		if (!t)
-- 
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