linux-kernel - [PATCH 4/6] mm, hwpoison: avoid unneeded page_mapped_in_vma() overhead in collect_procs

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Date:   Tue, 30 Aug 2022 20:36:02 +0800
From:   Miaohe Lin <linmiaohe@...wei.com>
To:     <akpm@...ux-foundation.org>, <naoya.horiguchi@....com>
CC:     <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
        <linmiaohe@...wei.com>
Subject: [PATCH 4/6] mm, hwpoison: avoid unneeded page_mapped_in_vma() overhead in collect_procs_anon()

If vma->vm_mm != t->mm, there's no need to call page_mapped_in_vma() as
add_to_kill() won't be called in this case. Move up the mm check to avoid
possible unneeded calling to page_mapped_in_vma().

Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
---
 mm/memory-failure.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 69c4d1b48ad6..904c2b6284a4 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -521,11 +521,11 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill,
 		anon_vma_interval_tree_foreach(vmac, &av->rb_root,
 					       pgoff, pgoff) {
 			vma = vmac->vma;
+			if (vma->vm_mm != t->mm)
+				continue;
 			if (!page_mapped_in_vma(page, vma))
 				continue;
-			if (vma->vm_mm == t->mm)
-				add_to_kill(t, page, FSDAX_INVALID_PGOFF, vma,
-					    to_kill);
+			add_to_kill(t, page, FSDAX_INVALID_PGOFF, vma, to_kill);
 		}
 	}
 	read_unlock(&tasklist_lock);
-- 
2.23.0