linux-kernel - [PATCH v2] mm: huge_memory: convert split_huge_pages

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Message-ID: <20221230093020.9664-1-wangkefeng.wang@huawei.com>
Date:   Fri, 30 Dec 2022 17:30:20 +0800
From:   Kefeng Wang <wangkefeng.wang@...wei.com>
To:     Andrew Morton <akpm@...ux-foundation.org>, <linux-mm@...ck.org>
CC:     <linux-kernel@...r.kernel.org>, <willy@...radead.org>,
        Kefeng Wang <wangkefeng.wang@...wei.com>
Subject: [PATCH v2] mm: huge_memory: convert split_huge_pages_all() to use a folio

Straightforwardly convert split_huge_pages_all() to use a folio.

Signed-off-by: Kefeng Wang <wangkefeng.wang@...wei.com>
---
- adjust indenting of code pointed by Matthew

 mm/huge_memory.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 266c4b557946..46e86293935b 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2932,6 +2932,7 @@ static void split_huge_pages_all(void)
 {
 	struct zone *zone;
 	struct page *page;
+	struct folio *folio;
 	unsigned long pfn, max_zone_pfn;
 	unsigned long total = 0, split = 0;
 
@@ -2944,24 +2945,32 @@ static void split_huge_pages_all(void)
 			int nr_pages;
 
 			page = pfn_to_online_page(pfn);
-			if (!page || !get_page_unless_zero(page))
+			if (!page || PageTail(page))
+				continue;
+			folio = page_folio(page);
+			if (!folio_try_get(folio))
 				continue;
 
-			if (zone != page_zone(page))
+			if (unlikely(page_folio(page) != folio))
+				goto next;
+
+			if (zone != folio_zone(folio))
 				goto next;
 
-			if (!PageHead(page) || PageHuge(page) || !PageLRU(page))
+			if (!folio_test_large(folio) ||
+			    folio_test_hugetlb(folio) ||
+			    !folio_test_lru(folio))
 				goto next;
 
 			total++;
-			lock_page(page);
-			nr_pages = thp_nr_pages(page);
-			if (!split_huge_page(page))
+			folio_lock(folio);
+			nr_pages = folio_nr_pages(folio);
+			if (!split_folio(folio))
 				split++;
 			pfn += nr_pages - 1;
-			unlock_page(page);
+			folio_unlock(folio);
 next:
-			put_page(page);
+			folio_put(folio);
 			cond_resched();
 		}
 	}
-- 
2.35.3