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From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: akpm@linux-foundation.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
	Jeff Layton <jlayton@kernel.org>
Subject: [PATCH v10 05/33] mm: Add folio reference count functions
Date: Tue, 11 May 2021 22:47:07 +0100
Message-ID: <20210511214735.1836149-6-willy@infradead.org> (raw)
In-Reply-To: <20210511214735.1836149-1-willy@infradead.org>

These functions mirror their page reference counterparts.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
---
 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 7ad46f45df39..85816b2c0496 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 int page_ref_add_unless(struct page *page, int nr, int u)
 {
 	int ret = atomic_add_unless(&page->_refcount, nr, u);
@@ -170,6 +242,11 @@ static inline int page_ref_add_unless(struct page *page, int nr, int u)
 	return ret;
 }
 
+static inline int 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 index

Thread overview: 96+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-11 21:47 [PATCH v10 00/33] Memory folios Matthew Wilcox (Oracle)
2021-05-11 21:47 ` [PATCH v10 01/33] mm: Introduce struct folio Matthew Wilcox (Oracle)
2021-05-14 10:34   ` Vlastimil Babka
2021-05-14 10:40   ` Vlastimil Babka
2021-05-14 11:47     ` Matthew Wilcox
2021-05-15 10:55   ` William Kucharski
2021-05-15 20:14     ` Matthew Wilcox
2021-05-16 19:26       ` William Kucharski
2021-05-27  8:09   ` Christoph Hellwig
2021-05-11 21:47 ` [PATCH v10 02/33] mm: Add folio_pgdat and folio_zone Matthew Wilcox (Oracle)
2021-05-14 10:35   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 03/33] mm/vmstat: Add functions to account folio statistics Matthew Wilcox (Oracle)
2021-05-14 10:36   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 04/33] mm/debug: Add VM_BUG_ON_FOLIO and VM_WARN_ON_ONCE_FOLIO Matthew Wilcox (Oracle)
2021-05-14 10:44   ` Vlastimil Babka
2021-05-11 21:47 ` Matthew Wilcox (Oracle) [this message]
2021-05-14 11:04   ` [PATCH v10 05/33] mm: Add folio reference count functions Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 06/33] mm: Add folio_put Matthew Wilcox (Oracle)
2021-05-14 11:52   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 07/33] mm: Add folio_get Matthew Wilcox (Oracle)
2021-05-14 11:56   ` Vlastimil Babka
2021-05-14 14:24     ` Matthew Wilcox
2021-05-14 15:39       ` Vlastimil Babka
2021-05-27  8:10       ` Christoph Hellwig
2021-05-27 22:53         ` Andrew Morton
2021-05-11 21:47 ` [PATCH v10 08/33] mm: Add folio_try_get_rcu Matthew Wilcox (Oracle)
2021-05-14 12:11   ` Vlastimil Babka
2021-05-27  8:16   ` Christoph Hellwig
2021-06-05  4:26     ` Matthew Wilcox
2021-06-06 14:13       ` Christoph Hellwig
2021-05-11 21:47 ` [PATCH v10 09/33] mm: Add folio flag manipulation functions Matthew Wilcox (Oracle)
2021-05-14 15:29   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 10/33] mm: Add folio_young and folio_idle Matthew Wilcox (Oracle)
2021-05-14 15:33   ` Vlastimil Babka
2021-05-27  8:17   ` Christoph Hellwig
2021-05-11 21:47 ` [PATCH v10 11/33] mm: Handle per-folio private data Matthew Wilcox (Oracle)
2021-05-14 15:41   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 12/33] mm/filemap: Add folio_index, folio_file_page and folio_contains Matthew Wilcox (Oracle)
2021-05-14 15:55   ` Vlastimil Babka
2021-05-15 15:51     ` Matthew Wilcox
2021-05-11 21:47 ` [PATCH v10 13/33] mm/filemap: Add folio_next_index Matthew Wilcox (Oracle)
2021-05-14 17:07   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 14/33] mm/filemap: Add folio_offset and folio_file_offset Matthew Wilcox (Oracle)
2021-05-14 17:08   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 15/33] mm/util: Add folio_mapping and folio_file_mapping Matthew Wilcox (Oracle)
2021-05-14 17:29   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 16/33] mm: Add folio_mapcount Matthew Wilcox (Oracle)
2021-05-14 17:39   ` Vlastimil Babka
2021-05-18 18:45   ` Matthew Wilcox
2021-05-11 21:47 ` [PATCH v10 17/33] mm/memcg: Add folio wrappers for various functions Matthew Wilcox (Oracle)
2021-05-18  9:57   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 18/33] mm/filemap: Add folio_unlock Matthew Wilcox (Oracle)
2021-05-18 10:06   ` Vlastimil Babka
2021-05-18 11:30     ` Matthew Wilcox
2021-05-11 21:47 ` [PATCH v10 19/33] mm/filemap: Add folio_lock Matthew Wilcox (Oracle)
2021-05-18 10:26   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 20/33] mm/filemap: Add folio_lock_killable Matthew Wilcox (Oracle)
2021-05-18 10:31   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 21/33] mm/filemap: Add __folio_lock_async Matthew Wilcox (Oracle)
2021-05-18 10:34   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 22/33] mm/filemap: Add __folio_lock_or_retry Matthew Wilcox (Oracle)
2021-05-18 10:38   ` Vlastimil Babka
2021-05-18 10:45     ` Vlastimil Babka
2021-05-18 13:35     ` Matthew Wilcox
2021-05-11 21:47 ` [PATCH v10 23/33] mm/filemap: Add folio_wait_locked Matthew Wilcox (Oracle)
2021-05-18 10:41   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 24/33] mm/swap: Add folio_rotate_reclaimable Matthew Wilcox (Oracle)
2021-05-18 10:48   ` Vlastimil Babka
2021-05-27  8:19   ` Christoph Hellwig
2021-05-11 21:47 ` [PATCH v10 25/33] mm/filemap: Add folio_end_writeback Matthew Wilcox (Oracle)
2021-05-18 11:08   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 26/33] mm/writeback: Add folio_wait_writeback Matthew Wilcox (Oracle)
2021-05-18 11:12   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 27/33] mm/writeback: Add folio_wait_stable Matthew Wilcox (Oracle)
2021-05-18 11:42   ` Vlastimil Babka
2021-05-18 13:55     ` Matthew Wilcox
2021-05-11 21:47 ` [PATCH v10 28/33] mm/filemap: Add folio_wait_bit Matthew Wilcox (Oracle)
2021-05-18 11:51   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 29/33] mm/filemap: Add folio_wake_bit Matthew Wilcox (Oracle)
2021-05-18 11:53   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 30/33] mm/filemap: Convert page wait queues to be folios Matthew Wilcox (Oracle)
2021-05-18 12:23   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 31/33] mm/filemap: Add folio private_2 functions Matthew Wilcox (Oracle)
2021-05-18 12:26   ` Vlastimil Babka
2021-05-27  8:21   ` Christoph Hellwig
2021-05-11 21:47 ` [PATCH v10 32/33] fs/netfs: Add folio fscache functions Matthew Wilcox (Oracle)
2021-05-18 13:48   ` Vlastimil Babka
2021-05-27  8:23   ` Christoph Hellwig
2021-05-11 21:47 ` [PATCH v10 33/33] mm: Add folio_mapped Matthew Wilcox (Oracle)
2021-05-18 14:17   ` Vlastimil Babka
2021-05-27  8:31   ` Christoph Hellwig
2021-05-13 14:50 ` [PATCH v10 00/33] Memory folios Matthew Wilcox
2021-05-15 10:26 ` William Kucharski
2021-06-04  1:07 ` Matteo Croce
2021-06-04  2:13   ` Matthew Wilcox
2021-06-08 14:56     ` Matteo Croce

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