linux-kernel - [PATCH 1/2] mm/memory_hotplug: remove head page reference in do_migrate

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Date:   Mon, 23 Jan 2023 12:23:46 -0800
From:   Sidhartha Kumar <sidhartha.kumar@...cle.com>
To:     linux-kernel@...r.kernel.org, linux-mm@...ck.org
Cc:     akpm@...ux-foundation.org, willy@...radead.org, david@...hat.com,
        osalvador@...e.de, Sidhartha Kumar <sidhartha.kumar@...cle.com>
Subject: [PATCH 1/2] mm/memory_hotplug: remove head page reference in do_migrate_range

The head page variable is not needed as we can use folio equivalent
functions.

Signed-off-by: Sidhartha Kumar <sidhartha.kumar@...cle.com>
---
 mm/memory_hotplug.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index a1e8c3e9ab08..ad09189786b1 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1624,7 +1624,7 @@ static int
 do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 {
 	unsigned long pfn;
-	struct page *page, *head;
+	struct page *page;
 	int ret = 0;
 	LIST_HEAD(source);
 	static DEFINE_RATELIMIT_STATE(migrate_rs, DEFAULT_RATELIMIT_INTERVAL,
@@ -1637,14 +1637,13 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 			continue;
 		page = pfn_to_page(pfn);
 		folio = page_folio(page);
-		head = &folio->page;
 
-		if (PageHuge(page)) {
-			pfn = page_to_pfn(head) + compound_nr(head) - 1;
+		if (folio_test_hugetlb(folio)) {
+			pfn = folio_pfn(folio) + folio_nr_pages(folio) - 1;
 			isolate_hugetlb(folio, &source);
 			continue;
-		} else if (PageTransHuge(page))
-			pfn = page_to_pfn(head) + thp_nr_pages(page) - 1;
+		} else if (folio_test_transhuge(folio))
+			pfn = folio_pfn(folio) + thp_nr_pages(page) - 1;
 
 		/*
 		 * HWPoison pages have elevated reference counts so the migration would
-- 
2.39.1