Commit c4ed6ebf authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

mm/memcg: Convert uncharge_page() to uncharge_folio() 



Use a folio rather than a page to ensure that we're only operating on
base or head pages, and not tail pages.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
parent 8f425e4e

mm/memcontrol.c

+15 −16
Original line number Diff line number Diff line
@@ -6794,24 +6794,23 @@ static void uncharge_batch(const struct uncharge_gather *ug) 
	memcg_check_events(ug->memcg, ug->nid);

	local_irq_restore(flags);



	/* drop reference from uncharge_page */

	/* drop reference from uncharge_folio */

	css_put(&ug->memcg->css);

}



static void uncharge_page(struct page *page, struct uncharge_gather *ug)

static void uncharge_folio(struct folio *folio, struct uncharge_gather *ug)

{

	struct folio *folio = page_folio(page);

	unsigned long nr_pages;

	long nr_pages;

	struct mem_cgroup *memcg;

	struct obj_cgroup *objcg;

	bool use_objcg = PageMemcgKmem(page);

	bool use_objcg = folio_memcg_kmem(folio);



	VM_BUG_ON_PAGE(PageLRU(page), page);

	VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);



	/*

	 * Nobody should be changing or seriously looking at

	 * page memcg or objcg at this point, we have fully

	 * exclusive access to the page.

	 * folio memcg or objcg at this point, we have fully

	 * exclusive access to the folio.

	 */

	if (use_objcg) {

		objcg = __folio_objcg(folio);
@@ -6833,19 +6832,19 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug) 
			uncharge_gather_clear(ug);

		}

		ug->memcg = memcg;

		ug->nid = page_to_nid(page);

		ug->nid = folio_nid(folio);



		/* pairs with css_put in uncharge_batch */

		css_get(&memcg->css);

	}



	nr_pages = compound_nr(page);

	nr_pages = folio_nr_pages(folio);



	if (use_objcg) {

		ug->nr_memory += nr_pages;

		ug->nr_kmem += nr_pages;



		page->memcg_data = 0;

		folio->memcg_data = 0;

		obj_cgroup_put(objcg);

	} else {

		/* LRU pages aren't accounted at the root level */
@@ -6853,7 +6852,7 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug) 
			ug->nr_memory += nr_pages;

		ug->pgpgout++;



		page->memcg_data = 0;

		folio->memcg_data = 0;

	}



	css_put(&memcg->css);
@@ -6874,7 +6873,7 @@ void __mem_cgroup_uncharge(struct page *page) 
		return;



	uncharge_gather_clear(&ug);

	uncharge_page(page, &ug);

	uncharge_folio(page_folio(page), &ug);

	uncharge_batch(&ug);

}
@@ -6888,11 +6887,11 @@ void __mem_cgroup_uncharge(struct page *page) 
void __mem_cgroup_uncharge_list(struct list_head *page_list)

{

	struct uncharge_gather ug;

	struct page *page;

	struct folio *folio;



	uncharge_gather_clear(&ug);

	list_for_each_entry(page, page_list, lru)

		uncharge_page(page, &ug);

	list_for_each_entry(folio, page_list, lru)

		uncharge_folio(folio, &ug);

	if (ug.memcg)

		uncharge_batch(&ug);

}