[PATCH v13 046/137] mm/memcg: Convert mem_cgroup_move_account() to use a folio

Matthew Wilcox (Oracle)
2021-07-12T03:32:42Z

This saves dozens of bytes of text by eliminating a lot of calls to
compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
mm/memcontrol.c | 37 +++++++++++++++++++------------------
1 file changed, 19 insertions(+), 18 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index cff267c59f4d..63cebdd48c27 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5590,38 +5590,39 @@ 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_transhuge(folio)) {
__mod_lruvec_state(from_vec, NR_ANON_THPS,
-nr_pages);
__mod_lruvec_state(to_vec, NR_ANON_THPS,
@@ -5632,18 +5633,18 @@ static int mem_cgroup_move_account(struct page *page,
__mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages);
__mod_lruvec_state(to_vec, NR_FILE_PAGES, nr_pages);

- if (PageSwapBacked(page)) {
+ if (folio_swapbacked(folio)) {
__mod_lruvec_state(from_vec, NR_SHMEM, -nr_pages);
__mod_lruvec_state(to_vec, NR_SHMEM, nr_pages);
}

- if (page_mapped(page)) {
+ if (folio_mapped(folio)) {
__mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages);
__mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages);
}

- if (PageDirty(page)) {
- struct address_space *mapping = page_mapping(page);
+ if (folio_dirty(folio)) {
+ struct address_space *mapping = folio_mapping(folio);

if (mapping_can_writeback(mapping)) {
__mod_lruvec_state(from_vec, NR_FILE_DIRTY,
@@ -5654,7 +5655,7 @@ static int mem_cgroup_move_account(struct page *page,
}
}

- if (PageWriteback(page)) {
+ if (folio_writeback(folio)) {
__mod_lruvec_state(from_vec, NR_WRITEBACK, -nr_pages);
__mod_lruvec_state(to_vec, NR_WRITEBACK, nr_pages);
}
@@ -5677,12 +5678,12 @@ static int mem_cgroup_move_account(struct page *page,
css_get(&to->css);
css_put(&from->css);

- page->memcg_data = (unsigned long)to;
+ folio->memcg_data = (unsigned long)to;

__folio_memcg_unlock(from);

ret = 0;
- nid = page_to_nid(page);
+ nid = folio_nid(folio);

local_irq_disable();
mem_cgroup_charge_statistics(to, nr_pages);
@@ -5691,7 +5692,7 @@ static int mem_cgroup_move_account(struct page *page,
memcg_check_events(from, nid);
local_irq_enable();
out_unlock:
- unlock_page(page);
+ folio_unlock(folio);
out:
return ret;
}
--
2.30.2