Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Zi Yan <zi.yan@sent.com>
To:     linux-mm@kvack.org, Matthew Wilcox <willy@infradead.org>
Cc:     "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Roman Gushchin <guro@fb.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
        Yang Shi <shy828301@gmail.com>,
        Michal Hocko <mhocko@kernel.org>,
        John Hubbard <jhubbard@nvidia.com>,
        Ralph Campbell <rcampbell@nvidia.com>,
        David Nellans <dnellans@nvidia.com>, Zi Yan <ziy@nvidia.com>
Subject: [RFC PATCH 3/6] mm: page_owner: add support for splitting to any order in split page_owner.
Date:   Wed, 11 Nov 2020 15:40:05 -0500
Message-Id: <20201111204008.21332-4-zi.yan@sent.com>
In-Reply-To: <20201111204008.21332-1-zi.yan@sent.com>
References: <20201111204008.21332-1-zi.yan@sent.com>
Reply-To: Zi Yan <ziy@nvidia.com>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

From: Zi Yan <ziy@nvidia.com>

It adds a new_order parameter to set new page order in page owner.
It prepares for upcoming changes to support split huge page to any lower
order.

Signed-off-by: Zi Yan <ziy@nvidia.com>
---
 include/linux/page_owner.h | 7 ++++---
 mm/huge_memory.c           | 2 +-
 mm/page_alloc.c            | 2 +-
 mm/page_owner.c            | 6 +++---
 4 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/include/linux/page_owner.h b/include/linux/page_owner.h
index 3468794f83d2..215cbb159568 100644
--- a/include/linux/page_owner.h
+++ b/include/linux/page_owner.h
@@ -31,10 +31,11 @@ static inline void set_page_owner(struct page *page,
 		__set_page_owner(page, order, gfp_mask);
 }
=20
-static inline void split_page_owner(struct page *page, unsigned int nr)
+static inline void split_page_owner(struct page *page, unsigned int nr,
+			unsigned int new_order)
 {
 	if (static_branch_unlikely(&page_owner_inited))
-		__split_page_owner(page, nr);
+		__split_page_owner(page, nr, new_order);
 }
 static inline void copy_page_owner(struct page *oldpage, struct page *newp=
age)
 {
@@ -60,7 +61,7 @@ static inline void set_page_owner(struct page *page,
 {
 }
 static inline void split_page_owner(struct page *page,
-			unsigned int order)
+			unsigned int nr, unsigned int new_order)
 {
 }
 static inline void copy_page_owner(struct page *oldpage, struct page *newp=
age)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index f599f5b9bf7f..8b7d771ee962 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2459,7 +2459,7 @@ static void __split_huge_page(struct page *page, stru=
ct list_head *list,
=20
 	ClearPageCompound(head);
=20
-	split_page_owner(head, nr);
+	split_page_owner(head, nr, 1);
=20
 	/* See comment in __split_huge_page_tail() */
 	if (PageAnon(head)) {
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d77220615fd5..a9eead0e091a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3284,7 +3284,7 @@ void split_page(struct page *page, unsigned int order)
=20
 	for (i =3D 1; i < (1 << order); i++)
 		set_page_refcounted(page + i);
-	split_page_owner(page, 1 << order);
+	split_page_owner(page, 1 << order, 1);
 }
 EXPORT_SYMBOL_GPL(split_page);
=20
diff --git a/mm/page_owner.c b/mm/page_owner.c
index b735a8eafcdb..2b7f7e9056dc 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -204,7 +204,7 @@ void __set_page_owner_migrate_reason(struct page *page,=
 int reason)
 	page_owner->last_migrate_reason =3D reason;
 }
=20
-void __split_page_owner(struct page *page, unsigned int nr)
+void __split_page_owner(struct page *page, unsigned int nr, unsigned int n=
ew_order)
 {
 	int i;
 	struct page_ext *page_ext =3D lookup_page_ext(page);
@@ -213,9 +213,9 @@ void __split_page_owner(struct page *page, unsigned int=
 nr)
 	if (unlikely(!page_ext))
 		return;
=20
-	for (i =3D 0; i < nr; i++) {
+	for (i =3D 0; i < nr; i +=3D (1 << new_order)) {
 		page_owner =3D get_page_owner(page_ext);
-		page_owner->order =3D 0;
+		page_owner->order =3D new_order;
 		page_ext =3D page_ext_next(page_ext);
 	}
 }
--=20
2.28.0