linux-kernel - [PATCH] mm,hugetlb: Allocate frozen pages in alloc_buddy_hugetlb

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Message-ID: <20250411132359.312708-1-osalvador@suse.de>
Date: Fri, 11 Apr 2025 15:23:59 +0200
From: Oscar Salvador <osalvador@...e.de>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Muchun Song <muchun.song@...ux.dev>,
	David Hildenbrand <david@...hat.com>,
	linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	Vlastimil Babka <vbabka@...e.cz>,
	Matthew Wilcox <willy@...radead.org>,
	Oscar Salvador <osalvador@...e.de>
Subject: [PATCH] mm,hugetlb: Allocate frozen pages in alloc_buddy_hugetlb_folio

alloc_buddy_hugetlb_folio() allocates a rmappable folio, then strips the
rmappable part and freezes it.
We can simplify all that by allocating frozen pages directly.

Suggested-by: Vlastimil Babka <vbabka@...e.cz>
Signed-off-by: Oscar Salvador <osalvador@...e.de>
---
 mm/hugetlb.c | 17 +----------------
 1 file changed, 1 insertion(+), 16 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index e3e6ac991b9c..83fa2b9f6fc4 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1950,7 +1950,6 @@ static struct folio *alloc_buddy_hugetlb_folio(struct hstate *h,
 	int order = huge_page_order(h);
 	struct folio *folio;
 	bool alloc_try_hard = true;
-	bool retry = true;
 
 	/*
 	 * By default we always try hard to allocate the folio with
@@ -1965,22 +1964,8 @@ static struct folio *alloc_buddy_hugetlb_folio(struct hstate *h,
 		gfp_mask |= __GFP_RETRY_MAYFAIL;
 	if (nid == NUMA_NO_NODE)
 		nid = numa_mem_id();
-retry:
-	folio = __folio_alloc(gfp_mask, order, nid, nmask);
-	/* Ensure hugetlb folio won't have large_rmappable flag set. */
-	if (folio)
-		folio_clear_large_rmappable(folio);
 
-	if (folio && !folio_ref_freeze(folio, 1)) {
-		folio_put(folio);
-		if (retry) {	/* retry once */
-			retry = false;
-			goto retry;
-		}
-		/* WOW!  twice in a row. */
-		pr_warn("HugeTLB unexpected inflated folio ref count\n");
-		folio = NULL;
-	}
+	folio = (struct folio *)__alloc_frozen_pages(gfp_mask, order, nid, nmask);
 
 	/*
 	 * If we did not specify __GFP_RETRY_MAYFAIL, but still got a
-- 
2.49.0