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From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: akpm@linux-foundation.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	linux-fsdevel@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
	Jeff Layton <jlayton@kernel.org>,
	"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	William Kucharski <william.kucharski@oracle.com>,
	David Howells <dhowells@redhat.com>
Subject: [PATCH v13 06/32] mm: Add folio reference count functions
Date: Mon, 12 Jul 2021 20:01:38 +0100	[thread overview]
Message-ID: <20210712190204.80979-7-willy@infradead.org> (raw)
In-Reply-To: <20210712190204.80979-1-willy@infradead.org>

These functions mirror their page reference counterparts.  Also add
the kernel-doc to the mm-api and correct the return type of
page_ref_add_unless() to bool.  No change to generated code.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: David Howells <dhowells@redhat.com>
---
 Documentation/core-api/mm-api.rst |  1 +
 include/linux/page_ref.h          | 88 ++++++++++++++++++++++++++++++-
 2 files changed, 88 insertions(+), 1 deletion(-)

diff --git a/Documentation/core-api/mm-api.rst b/Documentation/core-api/mm-api.rst
index 2a94e6164f80..5c459ee2acce 100644
--- a/Documentation/core-api/mm-api.rst
+++ b/Documentation/core-api/mm-api.rst
@@ -98,4 +98,5 @@ More Memory Management Functions
 .. kernel-doc:: include/linux/page-flags.h
 .. kernel-doc:: include/linux/mm.h
    :internal:
+.. kernel-doc:: include/linux/page_ref.h
 .. kernel-doc:: include/linux/mmzone.h
diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h
index 3a799de8ad52..717d53c9ddf1 100644
--- a/include/linux/page_ref.h
+++ b/include/linux/page_ref.h
@@ -67,9 +67,31 @@ static inline int page_ref_count(const struct page *page)
 	return atomic_read(&page->_refcount);
 }
 
+/**
+ * folio_ref_count - The reference count on this folio.
+ * @folio: The folio.
+ *
+ * The refcount is usually incremented by calls to folio_get() and
+ * decremented by calls to folio_put().  Some typical users of the
+ * folio refcount:
+ *
+ * - Each reference from a page table
+ * - The page cache
+ * - Filesystem private data
+ * - The LRU list
+ * - Pipes
+ * - Direct IO which references this page in the process address space
+ *
+ * Return: The number of references to this folio.
+ */
+static inline int folio_ref_count(const struct folio *folio)
+{
+	return page_ref_count(&folio->page);
+}
+
 static inline int page_count(const struct page *page)
 {
-	return atomic_read(&compound_head(page)->_refcount);
+	return folio_ref_count(page_folio(page));
 }
 
 static inline void set_page_count(struct page *page, int v)
@@ -79,6 +101,11 @@ static inline void set_page_count(struct page *page, int v)
 		__page_ref_set(page, v);
 }
 
+static inline void folio_set_count(struct folio *folio, int v)
+{
+	set_page_count(&folio->page, v);
+}
+
 /*
  * Setup the page count before being freed into the page allocator for
  * the first time (boot or memory hotplug)
@@ -95,6 +122,11 @@ static inline void page_ref_add(struct page *page, int nr)
 		__page_ref_mod(page, nr);
 }
 
+static inline void folio_ref_add(struct folio *folio, int nr)
+{
+	page_ref_add(&folio->page, nr);
+}
+
 static inline void page_ref_sub(struct page *page, int nr)
 {
 	atomic_sub(nr, &page->_refcount);
@@ -102,6 +134,11 @@ static inline void page_ref_sub(struct page *page, int nr)
 		__page_ref_mod(page, -nr);
 }
 
+static inline void folio_ref_sub(struct folio *folio, int nr)
+{
+	page_ref_sub(&folio->page, nr);
+}
+
 static inline int page_ref_sub_return(struct page *page, int nr)
 {
 	int ret = atomic_sub_return(nr, &page->_refcount);
@@ -111,6 +148,11 @@ static inline int page_ref_sub_return(struct page *page, int nr)
 	return ret;
 }
 
+static inline int folio_ref_sub_return(struct folio *folio, int nr)
+{
+	return page_ref_sub_return(&folio->page, nr);
+}
+
 static inline void page_ref_inc(struct page *page)
 {
 	atomic_inc(&page->_refcount);
@@ -118,6 +160,11 @@ static inline void page_ref_inc(struct page *page)
 		__page_ref_mod(page, 1);
 }
 
+static inline void folio_ref_inc(struct folio *folio)
+{
+	page_ref_inc(&folio->page);
+}
+
 static inline void page_ref_dec(struct page *page)
 {
 	atomic_dec(&page->_refcount);
@@ -125,6 +172,11 @@ static inline void page_ref_dec(struct page *page)
 		__page_ref_mod(page, -1);
 }
 
+static inline void folio_ref_dec(struct folio *folio)
+{
+	page_ref_dec(&folio->page);
+}
+
 static inline int page_ref_sub_and_test(struct page *page, int nr)
 {
 	int ret = atomic_sub_and_test(nr, &page->_refcount);
@@ -134,6 +186,11 @@ static inline int page_ref_sub_and_test(struct page *page, int nr)
 	return ret;
 }
 
+static inline int folio_ref_sub_and_test(struct folio *folio, int nr)
+{
+	return page_ref_sub_and_test(&folio->page, nr);
+}
+
 static inline int page_ref_inc_return(struct page *page)
 {
 	int ret = atomic_inc_return(&page->_refcount);
@@ -143,6 +200,11 @@ static inline int page_ref_inc_return(struct page *page)
 	return ret;
 }
 
+static inline int folio_ref_inc_return(struct folio *folio)
+{
+	return page_ref_inc_return(&folio->page);
+}
+
 static inline int page_ref_dec_and_test(struct page *page)
 {
 	int ret = atomic_dec_and_test(&page->_refcount);
@@ -152,6 +214,11 @@ static inline int page_ref_dec_and_test(struct page *page)
 	return ret;
 }
 
+static inline int folio_ref_dec_and_test(struct folio *folio)
+{
+	return page_ref_dec_and_test(&folio->page);
+}
+
 static inline int page_ref_dec_return(struct page *page)
 {
 	int ret = atomic_dec_return(&page->_refcount);
@@ -161,6 +228,11 @@ static inline int page_ref_dec_return(struct page *page)
 	return ret;
 }
 
+static inline int folio_ref_dec_return(struct folio *folio)
+{
+	return page_ref_dec_return(&folio->page);
+}
+
 static inline bool page_ref_add_unless(struct page *page, int nr, int u)
 {
 	bool ret = atomic_add_unless(&page->_refcount, nr, u);
@@ -170,6 +242,11 @@ static inline bool page_ref_add_unless(struct page *page, int nr, int u)
 	return ret;
 }
 
+static inline bool folio_ref_add_unless(struct folio *folio, int nr, int u)
+{
+	return page_ref_add_unless(&folio->page, nr, u);
+}
+
 static inline int page_ref_freeze(struct page *page, int count)
 {
 	int ret = likely(atomic_cmpxchg(&page->_refcount, count, 0) == count);
@@ -179,6 +256,11 @@ static inline int page_ref_freeze(struct page *page, int count)
 	return ret;
 }
 
+static inline int folio_ref_freeze(struct folio *folio, int count)
+{
+	return page_ref_freeze(&folio->page, count);
+}
+
 static inline void page_ref_unfreeze(struct page *page, int count)
 {
 	VM_BUG_ON_PAGE(page_count(page) != 0, page);
@@ -189,4 +271,8 @@ static inline void page_ref_unfreeze(struct page *page, int count)
 		__page_ref_unfreeze(page, count);
 }
 
+static inline void folio_ref_unfreeze(struct folio *folio, int count)
+{
+	page_ref_unfreeze(&folio->page, count);
+}
 #endif
-- 
2.30.2


  parent reply	other threads:[~2021-07-12 19:05 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-12 19:01 [PATCH v13a 00/32] Memory folios Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 01/32] mm: Convert get_page_unless_zero() to return bool Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 02/32] mm: Introduce struct folio Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 03/32] mm: Add folio_pgdat(), folio_zone() and folio_zonenum() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 04/32] mm/vmstat: Add functions to account folio statistics Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 05/32] mm/debug: Add VM_BUG_ON_FOLIO() and VM_WARN_ON_ONCE_FOLIO() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` Matthew Wilcox (Oracle) [this message]
2021-07-12 19:01 ` [PATCH v13 07/32] mm: Add folio_put() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 08/32] mm: Add folio_get() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 09/32] mm: Add folio_try_get_rcu() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 10/32] mm: Add folio flag manipulation functions Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 11/32] mm/lru: Add folio LRU functions Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 12/32] mm: Handle per-folio private data Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 13/32] mm/filemap: Add folio_index(), folio_file_page() and folio_contains() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 14/32] mm/filemap: Add folio_next_index() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 15/32] mm/filemap: Add folio_pos() and folio_file_pos() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 16/32] mm/util: Add folio_mapping() and folio_file_mapping() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 17/32] mm/filemap: Add folio_unlock() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 18/32] mm/filemap: Add folio_lock() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 19/32] mm/filemap: Add folio_lock_killable() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 20/32] mm/filemap: Add __folio_lock_async() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 21/32] mm/filemap: Add folio_wait_locked() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 22/32] mm/filemap: Add __folio_lock_or_retry() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 23/32] mm/swap: Add folio_rotate_reclaimable() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 24/32] mm/filemap: Add folio_end_writeback() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 25/32] mm/writeback: Add folio_wait_writeback() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 26/32] mm/writeback: Add folio_wait_stable() Matthew Wilcox (Oracle)
2021-07-12 19:01 ` [PATCH v13 27/32] mm/filemap: Add folio_wait_bit() Matthew Wilcox (Oracle)
2021-07-12 19:02 ` [PATCH v13 28/32] mm/filemap: Add folio_wake_bit() Matthew Wilcox (Oracle)
2021-07-12 19:02 ` [PATCH v13 29/32] mm/filemap: Convert page wait queues to be folios Matthew Wilcox (Oracle)
2021-07-12 19:02 ` [PATCH v13 30/32] mm/filemap: Add folio private_2 functions Matthew Wilcox (Oracle)
2021-07-12 19:02 ` [PATCH v13 31/32] fs/netfs: Add folio fscache functions Matthew Wilcox (Oracle)
2021-07-12 19:02 ` [PATCH v13 32/32] mm: Add folio_mapped() Matthew Wilcox (Oracle)

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