The patch titled
Subject: mm: memcg: add folio_memcg_check()
has been added to the -mm mm-unstable branch. Its filename is
mm-memcg-add-folio_memcg_check.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memcg-add-folio_memcg_check.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Subject: mm: memcg: add folio_memcg_check()
Date: Fri, 30 Dec 2022 15:08:42 +0800
Patch series "mm: convert page_idle/damon to use folios", v4.
This patch (of 8):
Convert page_memcg_check() into folio_memcg_check() and add a
page_memcg_check() wrapper. The behaviour of page_memcg_check() is
unchanged; tail pages always had a NULL ->memcg_data.
Link: https://lkml.kernel.org/r/20221230070849.63358-1-wangkefeng.wang@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20221230070849.63358-2-wangkefeng.wang@xxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: SeongJae Park <sj@xxxxxxxxxx>
Cc: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/include/linux/memcontrol.h~mm-memcg-add-folio_memcg_check
+++ a/include/linux/memcontrol.h
@@ -466,34 +466,34 @@ static inline struct mem_cgroup *folio_m
}
/*
- * page_memcg_check - get the memory cgroup associated with a page
- * @page: a pointer to the page struct
+ * folio_memcg_check - Get the memory cgroup associated with a folio.
+ * @folio: Pointer to the folio.
*
- * Returns a pointer to the memory cgroup associated with the page,
- * or NULL. This function unlike page_memcg() can take any page
- * as an argument. It has to be used in cases when it's not known if a page
+ * Returns a pointer to the memory cgroup associated with the folio,
+ * or NULL. This function unlike folio_memcg() can take any folio
+ * as an argument. It has to be used in cases when it's not known if a folio
* has an associated memory cgroup pointer or an object cgroups vector or
* an object cgroup.
*
- * For a non-kmem page any of the following ensures page and memcg binding
+ * For a non-kmem folio any of the following ensures folio and memcg binding
* stability:
*
- * - the page lock
+ * - the folio lock
* - LRU isolation
- * - lock_page_memcg()
+ * - lock_folio_memcg()
* - exclusive reference
* - mem_cgroup_trylock_pages()
*
- * For a kmem page a caller should hold an rcu read lock to protect memcg
- * associated with a kmem page from being released.
+ * For a kmem folio a caller should hold an rcu read lock to protect memcg
+ * associated with a kmem folio from being released.
*/
-static inline struct mem_cgroup *page_memcg_check(struct page *page)
+static inline struct mem_cgroup *folio_memcg_check(struct folio *folio)
{
/*
- * Because page->memcg_data might be changed asynchronously
- * for slab pages, READ_ONCE() should be used here.
+ * Because folio->memcg_data might be changed asynchronously
+ * for slabs, READ_ONCE() should be used here.
*/
- unsigned long memcg_data = READ_ONCE(page->memcg_data);
+ unsigned long memcg_data = READ_ONCE(folio->memcg_data);
if (memcg_data & MEMCG_DATA_OBJCGS)
return NULL;
@@ -508,6 +508,13 @@ static inline struct mem_cgroup *page_me
return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
}
+static inline struct mem_cgroup *page_memcg_check(struct page *page)
+{
+ if (PageTail(page))
+ return NULL;
+ return folio_memcg_check((struct folio *)page);
+}
+
static inline struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg)
{
struct mem_cgroup *memcg;
@@ -1170,6 +1177,11 @@ static inline struct mem_cgroup *folio_m
return NULL;
}
+static inline struct mem_cgroup *folio_memcg_check(struct folio *folio)
+{
+ return NULL;
+}
+
static inline struct mem_cgroup *page_memcg_check(struct page *page)
{
return NULL;
--- a/mm/memcontrol.c~mm-memcg-add-folio_memcg_check
+++ a/mm/memcontrol.c
@@ -2949,13 +2949,13 @@ struct mem_cgroup *mem_cgroup_from_obj_f
}
/*
- * page_memcg_check() is used here, because in theory we can encounter
+ * folio_memcg_check() is used here, because in theory we can encounter
* a folio where the slab flag has been cleared already, but
* slab->memcg_data has not been freed yet
- * page_memcg_check(page) will guarantee that a proper memory
+ * folio_memcg_check() will guarantee that a proper memory
* cgroup pointer or NULL will be returned.
*/
- return page_memcg_check(folio_page(folio, 0));
+ return folio_memcg_check(folio);
}
/*
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
buffer-add-b_folio-as-an-alias-of-b_page.patch
buffer-replace-obvious-uses-of-b_page-with-b_folio.patch
buffer-use-b_folio-in-touch_buffer.patch
buffer-use-b_folio-in-end_buffer_async_read.patch
buffer-use-b_folio-in-end_buffer_async_write.patch
page_io-remove-buffer_head-include.patch
buffer-use-b_folio-in-mark_buffer_dirty.patch
gfs2-replace-obvious-uses-of-b_page-with-b_folio.patch
jbd2-replace-obvious-uses-of-b_page-with-b_folio.patch
nilfs2-replace-obvious-uses-of-b_page-with-b_folio.patch
reiserfs-replace-obvious-uses-of-b_page-with-b_folio.patch
mpage-use-b_folio-in-do_mpage_readpage.patch
mm-memcg-add-folio_memcg_check.patch
