On Wed 30-06-21 05:00:30, Matthew Wilcox wrote:
> This saves dozens of bytes of text by eliminating a lot of calls to
> compound_head().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
> mm/memcontrol.c | 37 +++++++++++++++++++------------------
> 1 file changed, 19 insertions(+), 18 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index b94a6122f27d..95795b65ae3e 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -5585,38 +5585,39 @@ static int mem_cgroup_move_account(struct page *page,
> struct mem_cgroup *from,
> struct mem_cgroup *to)
> {
> + struct folio *folio = page_folio(page);
> struct lruvec *from_vec, *to_vec;
> struct pglist_data *pgdat;
> - unsigned int nr_pages = compound ? thp_nr_pages(page) : 1;
> + unsigned int nr_pages = compound ? folio_nr_pages(folio) : 1;
> int nid, ret;
>
> VM_BUG_ON(from == to);
> - VM_BUG_ON_PAGE(PageLRU(page), page);
> - VM_BUG_ON(compound && !PageTransHuge(page));
> + VM_BUG_ON_FOLIO(folio_lru(folio), folio);
> + VM_BUG_ON(compound && !folio_multi(folio));
>
> /*
> * Prevent mem_cgroup_migrate() from looking at
> * page's memory cgroup of its source page while we change it.
> */
> ret = -EBUSY;
> - if (!trylock_page(page))
> + if (!folio_trylock(folio))
> goto out;
>
> ret = -EINVAL;
> - if (page_memcg(page) != from)
> + if (folio_memcg(folio) != from)
> goto out_unlock;
>
> - pgdat = page_pgdat(page);
> + pgdat = folio_pgdat(folio);
> from_vec = mem_cgroup_lruvec(from, pgdat);
> to_vec = mem_cgroup_lruvec(to, pgdat);
>
> - lock_page_memcg(page);
> + folio_memcg_lock(folio);
>
> - if (PageAnon(page)) {
> - if (page_mapped(page)) {
> + if (folio_anon(folio)) {
> + if (folio_mapped(folio)) {
> __mod_lruvec_state(from_vec, NR_ANON_MAPPED, -nr_pages);
> __mod_lruvec_state(to_vec, NR_ANON_MAPPED, nr_pages);
> - if (PageTransHuge(page)) {
> + if (folio_multi(folio)) {
Shouldn't be folio_transhuge? The resulting code is the same but
folio_transhuge is more explicit and matches the THP aspect.
--
Michal Hocko
SUSE Labs
