linux-kernel - [PATCH v3 2/4] mm/hugetlb.c: Remove the unnecessary non_swap

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Message-ID: <20200723104636.GS32539@MiWiFi-R3L-srv>
Date:   Thu, 23 Jul 2020 18:46:36 +0800
From:   Baoquan He <bhe@...hat.com>
To:     linux-kernel@...r.kernel.org
Cc:     linux-mm@...ck.org, mike.kravetz@...cle.com, david@...hat.com,
        anshuman.khandual@....com, akpm@...ux-foundation.org
Subject: [PATCH v3 2/4] mm/hugetlb.c: Remove the unnecessary non_swap_entry()

If a swap entry tests positive for either is_[migration|hwpoison]_entry(),
then its swap_type() is among SWP_MIGRATION_READ, SWP_MIGRATION_WRITE and
SWP_HWPOISON. All these types >= MAX_SWAPFILES, exactly what is asserted
with non_swap_entry().

So the checking non_swap_entry() in is_hugetlb_entry_migration() and
is_hugetlb_entry_hwpoisoned() is redundant.

Let's remove it to optimize code.

Signed-off-by: Baoquan He <bhe@...hat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@...cle.com>
Reviewed-by: David Hildenbrand <david@...hat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@....com>
---
v2->v3:
  Updated patch log according to Anshuman's comment.

 mm/hugetlb.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 3569e731e66b..c14837854392 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3748,7 +3748,7 @@ bool is_hugetlb_entry_migration(pte_t pte)
 	if (huge_pte_none(pte) || pte_present(pte))
 		return false;
 	swp = pte_to_swp_entry(pte);
-	if (non_swap_entry(swp) && is_migration_entry(swp))
+	if (is_migration_entry(swp))
 		return true;
 	else
 		return false;
@@ -3761,7 +3761,7 @@ static bool is_hugetlb_entry_hwpoisoned(pte_t pte)
 	if (huge_pte_none(pte) || pte_present(pte))
 		return false;
 	swp = pte_to_swp_entry(pte);
-	if (non_swap_entry(swp) && is_hwpoison_entry(swp))
+	if (is_hwpoison_entry(swp))
 		return true;
 	else
 		return false;
-- 
2.17.2