On Tue 22-06-21 13:15:18, Matthew Wilcox wrote:
> 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@xxxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Thanks!
> ---
> mm/memcontrol.c | 27 +++++++++++++--------------
> 1 file changed, 13 insertions(+), 14 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 7423cb11eb88..7939e4e9118d 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -2700,9 +2700,9 @@ 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:
> *
> @@ -2711,7 +2711,7 @@ 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)
> @@ -6506,7 +6506,8 @@ 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);
> @@ -6514,7 +6515,7 @@ 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);
> @@ -6771,21 +6772,21 @@ 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);
> @@ -6794,14 +6795,12 @@ 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);
> -
> page_counter_charge(&memcg->memory, nr_pages);
> if (do_memsw_account())
> page_counter_charge(&memcg->memsw, nr_pages);
>
> 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
--
Michal Hocko
SUSE Labs
