[PATCH v1 10/12] mm: memcontrol: rename {un}lock_page_memcg() to {un}lock_page_objcg()

From: Muchun Song
Date: Sat Aug 14 2021 - 01:26:36 EST


Now the lock_page_memcg() does not lock a page and memcg binding, it
actually lock a page and objcg binding. So rename lock_page_memcg()
to lock_page_objcg().

This is just code cleanup without any functionality changes.

Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
---
Documentation/admin-guide/cgroup-v1/memory.rst | 2 +-
fs/buffer.c | 8 ++++----
include/linux/memcontrol.h | 14 +++++++-------
mm/filemap.c | 2 +-
mm/huge_memory.c | 4 ++--
mm/memcontrol.c | 24 ++++++++++++------------
mm/page-writeback.c | 6 +++---
mm/rmap.c | 14 +++++++-------
8 files changed, 37 insertions(+), 37 deletions(-)

diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst
index 41191b5fb69d..dd582312b91a 100644
--- a/Documentation/admin-guide/cgroup-v1/memory.rst
+++ b/Documentation/admin-guide/cgroup-v1/memory.rst
@@ -291,7 +291,7 @@ Lock order is as follows:

Page lock (PG_locked bit of page->flags)
mm->page_table_lock or split pte_lock
- lock_page_memcg (memcg->move_lock)
+ lock_page_objcg (memcg->move_lock)
mapping->i_pages lock
lruvec->lru_lock.

diff --git a/fs/buffer.c b/fs/buffer.c
index 88123f84885a..c3d20ebb1d0b 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -635,14 +635,14 @@ int __set_page_dirty_buffers(struct page *page)
* Lock out page's memcg migration to keep PageDirty
* synchronized with per-memcg dirty page counters.
*/
- lock_page_memcg(page);
+ lock_page_objcg(page);
newly_dirty = !TestSetPageDirty(page);
spin_unlock(&mapping->private_lock);

if (newly_dirty)
__set_page_dirty(page, mapping, 1);

- unlock_page_memcg(page);
+ unlock_page_objcg(page);

if (newly_dirty)
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
@@ -1139,13 +1139,13 @@ void mark_buffer_dirty(struct buffer_head *bh)
struct page *page = bh->b_page;
struct address_space *mapping = NULL;

- lock_page_memcg(page);
+ lock_page_objcg(page);
if (!TestSetPageDirty(page)) {
mapping = page_mapping(page);
if (mapping)
__set_page_dirty(page, mapping, 0);
}
- unlock_page_memcg(page);
+ unlock_page_objcg(page);
if (mapping)
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
}
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 92c98a952bab..611e6a6d7b00 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -417,12 +417,12 @@ static inline struct obj_cgroup *folio_objcg(struct folio *folio)
* proper memory cgroup pointer. It's not safe to call this function
* against some type of folios, e.g. slab folios or ex-slab folios.
*
- * For a folio any of the following ensures folio and memcg binding
- * stability:
+ * For a page any of the following ensures page and objcg binding
+ * stability (But the folio can be reparented to its parent memcg):
*
* - the folio lock
* - LRU isolation
- * - lock_page_memcg()
+ * - lock_page_objcg()
* - exclusive reference
*
* Based on the stable binding of folio and objcg, for a folio any of the
@@ -970,8 +970,8 @@ extern bool cgroup_memory_noswap;

void folio_memcg_lock(struct folio *folio);
void folio_memcg_unlock(struct folio *folio);
-void lock_page_memcg(struct page *page);
-void unlock_page_memcg(struct page *page);
+void lock_page_objcg(struct page *page);
+void unlock_page_objcg(struct page *page);

void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val);

@@ -1388,11 +1388,11 @@ mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
{
}

-static inline void lock_page_memcg(struct page *page)
+static inline void lock_page_objcg(struct page *page)
{
}

-static inline void unlock_page_memcg(struct page *page)
+static inline void unlock_page_objcg(struct page *page)
{
}

diff --git a/mm/filemap.c b/mm/filemap.c
index 53913fced7ae..b5298fd17d14 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -112,7 +112,7 @@
* ->i_pages lock (page_remove_rmap->set_page_dirty)
* bdi.wb->list_lock (page_remove_rmap->set_page_dirty)
* ->inode->i_lock (page_remove_rmap->set_page_dirty)
- * ->memcg->move_lock (page_remove_rmap->lock_page_memcg)
+ * ->memcg->move_lock (page_remove_rmap->lock_page_objcg)
* bdi.wb->list_lock (zap_pte_range->set_page_dirty)
* ->inode->i_lock (zap_pte_range->set_page_dirty)
* ->private_lock (zap_pte_range->__set_page_dirty_buffers)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 731e1b894407..eb3c07c00d2c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2227,7 +2227,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
atomic_inc(&page[i]._mapcount);
}

- lock_page_memcg(page);
+ lock_page_objcg(page);
if (atomic_add_negative(-1, compound_mapcount_ptr(page))) {
/* Last compound_mapcount is gone. */
__mod_lruvec_page_state(page, NR_ANON_THPS,
@@ -2238,7 +2238,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
atomic_dec(&page[i]._mapcount);
}
}
- unlock_page_memcg(page);
+ unlock_page_objcg(page);
}

smp_wmb(); /* make pte visible before pmd */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 52a878081452..9464e6d2d735 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2135,18 +2135,18 @@ void folio_memcg_lock(struct folio *folio)
* When charge migration first begins, we can have multiple
* critical sections holding the fast-path RCU lock and one
* holding the slowpath move_lock. Track the task who has the
- * move_lock for unlock_page_memcg().
+ * move_lock for unlock_page_objcg().
*/
memcg->move_lock_task = current;
memcg->move_lock_flags = flags;
}
EXPORT_SYMBOL(folio_memcg_lock);

-void lock_page_memcg(struct page *page)
+void lock_page_objcg(struct page *page)
{
folio_memcg_lock(page_folio(page));
}
-EXPORT_SYMBOL(lock_page_memcg);
+EXPORT_SYMBOL(lock_page_objcg);

static void __folio_memcg_unlock(struct mem_cgroup *memcg)
{
@@ -2176,11 +2176,11 @@ void folio_memcg_unlock(struct folio *folio)
}
EXPORT_SYMBOL(folio_memcg_unlock);

-void unlock_page_memcg(struct page *page)
+void unlock_page_objcg(struct page *page)
{
folio_memcg_unlock(page_folio(page));
}
-EXPORT_SYMBOL(unlock_page_memcg);
+EXPORT_SYMBOL(unlock_page_objcg);

struct obj_stock {
#ifdef CONFIG_MEMCG_KMEM
@@ -2887,7 +2887,7 @@ static void commit_charge(struct folio *folio, struct obj_cgroup *objcg)
*
* - the page lock
* - LRU isolation
- * - lock_page_memcg()
+ * - lock_page_objcg()
* - exclusive reference
*/
folio->memcg_data = (unsigned long)objcg;
@@ -5826,7 +5826,7 @@ static int mem_cgroup_move_account(struct page *page,
* with (un)charging, migration, LRU putback, or anything else
* that would rely on a stable page's memory cgroup.
*
- * Note that lock_page_memcg is a memcg lock, not a page lock,
+ * Note that lock_page_objcg is a memcg lock, not a page lock,
* to save space. As soon as we switch page's memory cgroup to a
* new memcg that isn't locked, the above state can change
* concurrently again. Make sure we're truly done with it.
@@ -6281,7 +6281,7 @@ static void mem_cgroup_move_charge(void)
{
lru_add_drain_all();
/*
- * Signal lock_page_memcg() to take the memcg's move_lock
+ * Signal lock_page_objcg() to take the memcg's move_lock
* while we're moving its pages to another memcg. Then wait
* for already started RCU-only updates to finish.
*/
@@ -6313,14 +6313,14 @@ static void mem_cgroup_move_charge(void)
/*
* Moving its pages to another memcg is finished. Wait for already
* started RCU-only updates to finish to make sure that the caller
- * of lock_page_memcg() can unlock the correct move_lock. The
+ * of lock_page_objcg() can unlock the correct move_lock. The
* possible bad scenario would like:
*
* CPU0: CPU1:
* mem_cgroup_move_charge()
* walk_page_range()
*
- * lock_page_memcg(page)
+ * unlock_page_objcg(page)
* memcg = folio_memcg()
* spin_lock_irqsave(&memcg->move_lock)
* memcg->move_lock_task = current
@@ -6331,14 +6331,14 @@ static void mem_cgroup_move_charge(void)
* memcg_offline_kmem()
* memcg_reparent_objcgs() <== reparented
*
- * unlock_page_memcg(page)
+ * unlock_page_objcg(page)
* memcg = folio_memcg() <== memcg has been changed
* if (memcg->move_lock_task == current) <== false
* spin_unlock_irqrestore(&memcg->move_lock)
*
* Once mem_cgroup_move_charge() returns (it means that the cgroup_mutex
* would be released soon), the page can be reparented to its parent
- * memcg. When the unlock_page_memcg() is called for the page, we will
+ * memcg. When the unlock_page_objcg() is called for the page, we will
* miss unlock the move_lock. So using synchronize_rcu to wait for
* already started RCU-only updates to finish before this function
* returns (mem_cgroup_move_charge() and mem_cgroup_css_offline() are
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 5b171aa067c1..d8fd7308dd39 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2434,7 +2434,7 @@ EXPORT_SYMBOL(__set_page_dirty_no_writeback);
/*
* Helper function for set_page_dirty family.
*
- * Caller must hold lock_page_memcg().
+ * Caller must hold lock_page_objcg().
*
* NOTE: This relies on being atomic wrt interrupts.
*/
@@ -2468,7 +2468,7 @@ static void folio_account_dirtied(struct folio *folio,
/*
* Helper function for deaccounting dirty page without writeback.
*
- * Caller must hold lock_page_memcg().
+ * Caller must hold lock_page_objcg().
*/
void folio_account_cleaned(struct folio *folio, struct address_space *mapping,
struct bdi_writeback *wb)
@@ -2489,7 +2489,7 @@ void folio_account_cleaned(struct folio *folio, struct address_space *mapping,
* If warn is true, then emit a warning if the folio is not uptodate and has
* not been truncated.
*
- * The caller must hold lock_page_memcg().
+ * The caller must hold lock_page_objcg().
*/
void __folio_mark_dirty(struct folio *folio, struct address_space *mapping,
int warn)
diff --git a/mm/rmap.c b/mm/rmap.c
index 09c41e1f44d8..232494888628 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -32,7 +32,7 @@
* swap_lock (in swap_duplicate, swap_info_get)
* mmlist_lock (in mmput, drain_mmlist and others)
* mapping->private_lock (in __set_page_dirty_buffers)
- * lock_page_memcg move_lock (in __set_page_dirty_buffers)
+ * lock_page_objcg move_lock (in __set_page_dirty_buffers)
* i_pages lock (widely used)
* lruvec->lru_lock (in folio_lruvec_lock_irq)
* inode->i_lock (in set_page_dirty's __mark_inode_dirty)
@@ -1125,7 +1125,7 @@ void do_page_add_anon_rmap(struct page *page,
bool first;

if (unlikely(PageKsm(page)))
- lock_page_memcg(page);
+ lock_page_objcg(page);
else
VM_BUG_ON_PAGE(!PageLocked(page), page);

@@ -1153,7 +1153,7 @@ void do_page_add_anon_rmap(struct page *page,
}

if (unlikely(PageKsm(page))) {
- unlock_page_memcg(page);
+ unlock_page_objcg(page);
return;
}

@@ -1213,7 +1213,7 @@ void page_add_file_rmap(struct page *page, bool compound)
int i, nr = 1;

VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page);
- lock_page_memcg(page);
+ lock_page_objcg(page);
if (compound && PageTransHuge(page)) {
int nr_pages = thp_nr_pages(page);

@@ -1242,7 +1242,7 @@ void page_add_file_rmap(struct page *page, bool compound)
}
__mod_lruvec_page_state(page, NR_FILE_MAPPED, nr);
out:
- unlock_page_memcg(page);
+ unlock_page_objcg(page);
}

static void page_remove_file_rmap(struct page *page, bool compound)
@@ -1343,7 +1343,7 @@ static void page_remove_anon_compound_rmap(struct page *page)
*/
void page_remove_rmap(struct page *page, bool compound)
{
- lock_page_memcg(page);
+ lock_page_objcg(page);

if (!PageAnon(page)) {
page_remove_file_rmap(page, compound);
@@ -1382,7 +1382,7 @@ void page_remove_rmap(struct page *page, bool compound)
* faster for those pages still in swapcache.
*/
out:
- unlock_page_memcg(page);
+ unlock_page_objcg(page);
}

/*
--
2.11.0