Commit 3ecb0087 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

mm/memcg: Convert mem_cgroup_swapout() to take a folio 



This removes an assumption that THPs are the only kind of compound
pages and removes a couple of hidden calls to compound_head.  It
also documents that you can't pass a tail page to mem_cgroup_swapout().

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent 8927f647

include/linux/swap.h

+2 −2
Original line number Diff line number Diff line
@@ -741,7 +741,7 @@ static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask) 
#endif



#ifdef CONFIG_MEMCG_SWAP

extern void mem_cgroup_swapout(struct page *page, swp_entry_t entry);

void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry);

extern int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry);

static inline int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)

{
@@ -761,7 +761,7 @@ static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_p 
extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg);

extern bool mem_cgroup_swap_full(struct page *page);

#else

static inline void mem_cgroup_swapout(struct page *page, swp_entry_t entry)

static inline void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry)

{

}

mm/memcontrol.c

+11 −11
Original line number Diff line number Diff line
@@ -7116,19 +7116,19 @@ static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) 


/**

 * mem_cgroup_swapout - transfer a memsw charge to swap

 * @page: page whose memsw charge to transfer

 * @folio: folio whose memsw charge to transfer

 * @entry: swap entry to move the charge to

 *

 * Transfer the memsw charge of @page to @entry.

 * Transfer the memsw charge of @folio to @entry.

 */

void mem_cgroup_swapout(struct page *page, swp_entry_t entry)

void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry)

{

	struct mem_cgroup *memcg, *swap_memcg;

	unsigned int nr_entries;

	unsigned short oldid;



	VM_BUG_ON_PAGE(PageLRU(page), page);

	VM_BUG_ON_PAGE(page_count(page), page);

	VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);

	VM_BUG_ON_FOLIO(folio_ref_count(folio), folio);



	if (mem_cgroup_disabled())

		return;
@@ -7136,9 +7136,9 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) 
	if (cgroup_subsys_on_dfl(memory_cgrp_subsys))

		return;



	memcg = page_memcg(page);

	memcg = folio_memcg(folio);



	VM_WARN_ON_ONCE_PAGE(!memcg, page);

	VM_WARN_ON_ONCE_FOLIO(!memcg, folio);

	if (!memcg)

		return;
@@ -7148,16 +7148,16 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) 
	 * ancestor for the swap instead and transfer the memory+swap charge.

	 */

	swap_memcg = mem_cgroup_id_get_online(memcg);

	nr_entries = thp_nr_pages(page);

	nr_entries = folio_nr_pages(folio);

	/* Get references for the tail pages, too */

	if (nr_entries > 1)

		mem_cgroup_id_get_many(swap_memcg, nr_entries - 1);

	oldid = swap_cgroup_record(entry, mem_cgroup_id(swap_memcg),

				   nr_entries);

	VM_BUG_ON_PAGE(oldid, page);

	VM_BUG_ON_FOLIO(oldid, folio);

	mod_memcg_state(swap_memcg, MEMCG_SWAP, nr_entries);



	page->memcg_data = 0;

	folio->memcg_data = 0;



	if (!mem_cgroup_is_root(memcg))

		page_counter_uncharge(&memcg->memory, nr_entries);
@@ -7176,7 +7176,7 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) 
	 */

	VM_BUG_ON(!irqs_disabled());

	mem_cgroup_charge_statistics(memcg, -nr_entries);

	memcg_check_events(memcg, page_to_nid(page));

	memcg_check_events(memcg, folio_nid(folio));



	css_put(&memcg->css);

}

mm/vmscan.c

+1 −1
Original line number Diff line number Diff line
@@ -1288,7 +1288,7 @@ static int __remove_mapping(struct address_space *mapping, struct page *page, 


	if (PageSwapCache(page)) {

		swp_entry_t swap = { .val = page_private(page) };

		mem_cgroup_swapout(page, swap);

		mem_cgroup_swapout(folio, swap);

		if (reclaimed && !mapping_exiting(mapping))

			shadow = workingset_eviction(folio, target_memcg);

		__delete_from_swap_cache(page, swap, shadow);