[PATCH v13 039/137] mm/memcg: Convert commit_charge() to take a folio

Matthew Wilcox (Oracle)
2021-07-12T03:29:04Z

The memcg_data is only set on the head page, so enforce that by
typing it as a folio.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Michal Hocko <mhocko@suse.com>
---
mm/memcontrol.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f0f781dde37a..f64869c0e06e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2769,9 +2769,9 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
}
#endif

-static void commit_charge(struct page *page, struct mem_cgroup *memcg)
+static void commit_charge(struct folio *folio, struct mem_cgroup *memcg)
{
- VM_BUG_ON_PAGE(page_memcg(page), page);
+ VM_BUG_ON_FOLIO(folio_memcg(folio), folio);
/*
* Any of the following ensures page's memcg stability:
*
@@ -2780,7 +2780,7 @@ static void commit_charge(struct page *page, struct mem_cgroup *memcg)
* - lock_page_memcg()
* - exclusive reference
*/
- page->memcg_data = (unsigned long)memcg;
+ folio->memcg_data = (unsigned long)memcg;
}

static struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg)
@@ -6684,7 +6684,8 @@ void mem_cgroup_calculate_protection(struct mem_cgroup *root,
static int __mem_cgroup_charge(struct page *page, struct mem_cgroup *memcg,
gfp_t gfp)
{
- unsigned int nr_pages = thp_nr_pages(page);
+ struct folio *folio = page_folio(page);
+ unsigned int nr_pages = folio_nr_pages(folio);
int ret;

ret = try_charge(memcg, gfp, nr_pages);
@@ -6692,7 +6693,7 @@ static int __mem_cgroup_charge(struct page *page, struct mem_cgroup *memcg,
goto out;

css_get(&memcg->css);
- commit_charge(page, memcg);
+ commit_charge(folio, memcg);

local_irq_disable();
mem_cgroup_charge_statistics(memcg, nr_pages);
@@ -6952,21 +6953,21 @@ void mem_cgroup_uncharge_list(struct list_head *page_list)
*/
void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)
{
+ struct folio *newfolio = page_folio(newpage);
struct mem_cgroup *memcg;
- unsigned int nr_pages;
+ unsigned int nr_pages = folio_nr_pages(newfolio);
unsigned long flags;

VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage);
- VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
- VM_BUG_ON_PAGE(PageAnon(oldpage) != PageAnon(newpage), newpage);
- VM_BUG_ON_PAGE(PageTransHuge(oldpage) != PageTransHuge(newpage),
- newpage);
+ VM_BUG_ON_FOLIO(!folio_locked(newfolio), newfolio);
+ VM_BUG_ON_FOLIO(PageAnon(oldpage) != folio_anon(newfolio), newfolio);
+ VM_BUG_ON_FOLIO(compound_nr(oldpage) != nr_pages, newfolio);

if (mem_cgroup_disabled())
return;

/* Page cache replacement: new page already charged? */
- if (page_memcg(newpage))
+ if (folio_memcg(newfolio))
return;

memcg = page_memcg(oldpage);
@@ -6975,8 +6976,6 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)
return;

/* Force-charge the new page. The old one will be freed soon */
- nr_pages = thp_nr_pages(newpage);
-
if (!mem_cgroup_is_root(memcg)) {
page_counter_charge(&memcg->memory, nr_pages);
if (do_memsw_account())
@@ -6984,7 +6983,7 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)
}

css_get(&memcg->css);
- commit_charge(newpage, memcg);
+ commit_charge(newfolio, memcg);

local_irq_save(flags);
mem_cgroup_charge_statistics(memcg, nr_pages);
--
2.30.2