linux-kernel - [PATCH v2 18/28] hugetlb: Use try_grab_folio() instead of try_grab_compound

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Message-Id: <20220110042406.499429-19-willy@infradead.org>
Date:   Mon, 10 Jan 2022 04:23:56 +0000
From:   "Matthew Wilcox (Oracle)" <willy@...radead.org>
To:     linux-mm@...ck.org
Cc:     "Matthew Wilcox (Oracle)" <willy@...radead.org>,
        John Hubbard <jhubbard@...dia.com>,
        Christoph Hellwig <hch@...radead.org>,
        William Kucharski <william.kucharski@...cle.com>,
        linux-kernel@...r.kernel.org, Jason Gunthorpe <jgg@...pe.ca>
Subject: [PATCH v2 18/28] hugetlb: Use try_grab_folio() instead of try_grab_compound_head()

follow_hugetlb_page() only cares about success or failure, so it doesn't
need to know the type of the returned pointer, only whether it's NULL
or not.

Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
---
 include/linux/mm.h | 3 ---
 mm/gup.c           | 2 +-
 mm/hugetlb.c       | 7 +++----
 3 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index b249156f7cf1..c103c6401ecd 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1195,9 +1195,6 @@ static inline void get_page(struct page *page)
 }
 
 bool __must_check try_grab_page(struct page *page, unsigned int flags);
-struct page *try_grab_compound_head(struct page *page, int refs,
-				    unsigned int flags);
-
 
 static inline __must_check bool try_get_page(struct page *page)
 {
diff --git a/mm/gup.c b/mm/gup.c
index 719252fa0402..20703de2f107 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -146,7 +146,7 @@ struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags)
 	return NULL;
 }
 
-struct page *try_grab_compound_head(struct page *page,
+static inline struct page *try_grab_compound_head(struct page *page,
 		int refs, unsigned int flags)
 {
 	return &try_grab_folio(page, refs, flags)->page;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index abcd1785c629..ab67b13c4a71 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6072,7 +6072,7 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
 
 		if (pages) {
 			/*
-			 * try_grab_compound_head() should always succeed here,
+			 * try_grab_folio() should always succeed here,
 			 * because: a) we hold the ptl lock, and b) we've just
 			 * checked that the huge page is present in the page
 			 * tables. If the huge page is present, then the tail
@@ -6081,9 +6081,8 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
 			 * any way. So this page must be available at this
 			 * point, unless the page refcount overflowed:
 			 */
-			if (WARN_ON_ONCE(!try_grab_compound_head(pages[i],
-								 refs,
-								 flags))) {
+			if (WARN_ON_ONCE(!try_grab_folio(pages[i], refs,
+							 flags))) {
 				spin_unlock(ptl);
 				remainder = 0;
 				err = -ENOMEM;
-- 
2.33.0