Commit f70ad448 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

mm/memcg: Add folio_memcg_lock() and folio_memcg_unlock() 



These are the folio equivalents of lock_page_memcg() and
unlock_page_memcg().

lock_page_memcg() and unlock_page_memcg() have too many callers to be
easily replaced in a single patch, so reimplement them as wrappers for
now to be cleaned up later when enough callers have been converted to
use folios.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarMike Rapoport <rppt@linux.ibm.com>
Reviewed-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
parent 9d8053fc

include/linux/memcontrol.h

+10 −0
Original line number Diff line number Diff line
@@ -978,6 +978,8 @@ void mem_cgroup_print_oom_group(struct mem_cgroup *memcg); 
extern bool cgroup_memory_noswap;

#endif



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);
@@ -1397,6 +1399,14 @@ static inline void unlock_page_memcg(struct page *page) 
{

}



static inline void folio_memcg_lock(struct folio *folio)

{

}



static inline void folio_memcg_unlock(struct folio *folio)

{

}



static inline void mem_cgroup_handle_over_high(void)

{

}

mm/memcontrol.c

+29 −16
Original line number Diff line number Diff line
@@ -1933,18 +1933,17 @@ void mem_cgroup_print_oom_group(struct mem_cgroup *memcg) 
}



/**

 * lock_page_memcg - lock a page and memcg binding

 * @page: the page

 * folio_memcg_lock - Bind a folio to its memcg.

 * @folio: The folio.

 *

 * This function protects unlocked LRU pages from being moved to

 * This function prevents unlocked LRU folios from being moved to

 * another cgroup.

 *

 * It ensures lifetime of the locked memcg. Caller is responsible

 * for the lifetime of the page.

 * It ensures lifetime of the bound memcg.  The caller is responsible

 * for the lifetime of the folio.

 */

void lock_page_memcg(struct page *page)

void folio_memcg_lock(struct folio *folio)

{

	struct page *head = compound_head(page); /* rmap on tail pages */

	struct mem_cgroup *memcg;

	unsigned long flags;
@@ -1958,7 +1957,7 @@ void lock_page_memcg(struct page *page) 
	if (mem_cgroup_disabled())

		return;

again:

	memcg = page_memcg(head);

	memcg = folio_memcg(folio);

	if (unlikely(!memcg))

		return;
@@ -1972,7 +1971,7 @@ void lock_page_memcg(struct page *page) 
		return;



	spin_lock_irqsave(&memcg->move_lock, flags);

	if (memcg != page_memcg(head)) {

	if (memcg != folio_memcg(folio)) {

		spin_unlock_irqrestore(&memcg->move_lock, flags);

		goto again;

	}
@@ -1986,9 +1985,15 @@ void lock_page_memcg(struct page *page) 
	memcg->move_lock_task = current;

	memcg->move_lock_flags = flags;

}

EXPORT_SYMBOL(folio_memcg_lock);



void lock_page_memcg(struct page *page)

{

	folio_memcg_lock(page_folio(page));

}

EXPORT_SYMBOL(lock_page_memcg);



static void __unlock_page_memcg(struct mem_cgroup *memcg)

static void __folio_memcg_unlock(struct mem_cgroup *memcg)

{

	if (memcg && memcg->move_lock_task == current) {

		unsigned long flags = memcg->move_lock_flags;
@@ -2003,14 +2008,22 @@ static void __unlock_page_memcg(struct mem_cgroup *memcg) 
}



/**

 * unlock_page_memcg - unlock a page and memcg binding

 * @page: the page

 * folio_memcg_unlock - Release the binding between a folio and its memcg.

 * @folio: The folio.

 *

 * This releases the binding created by folio_memcg_lock().  This does

 * not change the accounting of this folio to its memcg, but it does

 * permit others to change it.

 */

void unlock_page_memcg(struct page *page)

void folio_memcg_unlock(struct folio *folio)

{

	struct page *head = compound_head(page);

	__folio_memcg_unlock(folio_memcg(folio));

}

EXPORT_SYMBOL(folio_memcg_unlock);



	__unlock_page_memcg(page_memcg(head));

void unlock_page_memcg(struct page *page)

{

	folio_memcg_unlock(page_folio(page));

}

EXPORT_SYMBOL(unlock_page_memcg);
@@ -5643,7 +5656,7 @@ static int mem_cgroup_move_account(struct page *page, 


	page->memcg_data = (unsigned long)to;



	__unlock_page_memcg(from);

	__folio_memcg_unlock(from);



	ret = 0;

	nid = page_to_nid(page);