mm: memcontrol: switch to native NR_FILE_PAGES and NR_SHMEM counters

Memcg maintains private MEMCG_CACHE and NR_SHMEM counters.  This
divergence from the generic VM accounting means unnecessary code overhead,
and creates a dependency for memcg that page->mapping is set up at the
time of charging, so that page types can be told apart.

Convert the generic accounting sites to mod_lruvec_page_state and friends
to maintain the per-cgroup vmstat counters of NR_FILE_PAGES and NR_SHMEM.
The page is already locked in these places, so page->mem_cgroup is stable;
we only need minimal tweaks of two mem_cgroup_migrate() calls to ensure
it's set up in time.

Then replace MEMCG_CACHE with NR_FILE_PAGES and delete the private
NR_SHMEM accounting sites.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-10-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Johannes Weiner 2020-06-03 16:01:54 -07:00 committed by Linus Torvalds
parent 9da7b52168
commit 0d1c20722a
6 changed files with 50 additions and 43 deletions

View File

@ -29,8 +29,7 @@ struct kmem_cache;
/* Cgroup-specific page state, on top of universal node page state */
enum memcg_stat_item {
MEMCG_CACHE = NR_VM_NODE_STAT_ITEMS,
MEMCG_RSS,
MEMCG_RSS = NR_VM_NODE_STAT_ITEMS,
MEMCG_RSS_HUGE,
MEMCG_SWAP,
MEMCG_SOCK,

View File

@ -199,9 +199,9 @@ static void unaccount_page_cache_page(struct address_space *mapping,
nr = hpage_nr_pages(page);
__mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, -nr);
__mod_lruvec_page_state(page, NR_FILE_PAGES, -nr);
if (PageSwapBacked(page)) {
__mod_node_page_state(page_pgdat(page), NR_SHMEM, -nr);
__mod_lruvec_page_state(page, NR_SHMEM, -nr);
if (PageTransHuge(page))
__dec_node_page_state(page, NR_SHMEM_THPS);
} else if (PageTransHuge(page)) {
@ -802,21 +802,22 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
new->mapping = mapping;
new->index = offset;
mem_cgroup_migrate(old, new);
xas_lock_irqsave(&xas, flags);
xas_store(&xas, new);
old->mapping = NULL;
/* hugetlb pages do not participate in page cache accounting. */
if (!PageHuge(old))
__dec_node_page_state(old, NR_FILE_PAGES);
__dec_lruvec_page_state(old, NR_FILE_PAGES);
if (!PageHuge(new))
__inc_node_page_state(new, NR_FILE_PAGES);
__inc_lruvec_page_state(new, NR_FILE_PAGES);
if (PageSwapBacked(old))
__dec_node_page_state(old, NR_SHMEM);
__dec_lruvec_page_state(old, NR_SHMEM);
if (PageSwapBacked(new))
__inc_node_page_state(new, NR_SHMEM);
__inc_lruvec_page_state(new, NR_SHMEM);
xas_unlock_irqrestore(&xas, flags);
mem_cgroup_migrate(old, new);
if (freepage)
freepage(old);
put_page(old);
@ -867,7 +868,7 @@ static int __add_to_page_cache_locked(struct page *page,
/* hugetlb pages do not participate in page cache accounting */
if (!huge)
__inc_node_page_state(page, NR_FILE_PAGES);
__inc_lruvec_page_state(page, NR_FILE_PAGES);
unlock:
xas_unlock_irq(&xas);
} while (xas_nomem(&xas, gfp_mask & GFP_RECLAIM_MASK));

View File

@ -1844,12 +1844,18 @@ out_unlock:
}
if (nr_none) {
struct zone *zone = page_zone(new_page);
__mod_node_page_state(zone->zone_pgdat, NR_FILE_PAGES, nr_none);
struct lruvec *lruvec;
/*
* XXX: We have started try_charge and pinned the
* memcg, but the page isn't committed yet so we
* cannot use mod_lruvec_page_state(). This hackery
* will be cleaned up when remove the page->mapping
* dependency from memcg and fully charge above.
*/
lruvec = mem_cgroup_lruvec(memcg, page_pgdat(new_page));
__mod_lruvec_state(lruvec, NR_FILE_PAGES, nr_none);
if (is_shmem)
__mod_node_page_state(zone->zone_pgdat,
NR_SHMEM, nr_none);
__mod_lruvec_state(lruvec, NR_SHMEM, nr_none);
}
xa_locked:

View File

@ -842,11 +842,6 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
*/
if (PageAnon(page))
__mod_memcg_state(memcg, MEMCG_RSS, nr_pages);
else {
__mod_memcg_state(memcg, MEMCG_CACHE, nr_pages);
if (PageSwapBacked(page))
__mod_memcg_state(memcg, NR_SHMEM, nr_pages);
}
if (abs(nr_pages) > 1) {
VM_BUG_ON_PAGE(!PageTransHuge(page), page);
@ -1392,7 +1387,7 @@ static char *memory_stat_format(struct mem_cgroup *memcg)
(u64)memcg_page_state(memcg, MEMCG_RSS) *
PAGE_SIZE);
seq_buf_printf(&s, "file %llu\n",
(u64)memcg_page_state(memcg, MEMCG_CACHE) *
(u64)memcg_page_state(memcg, NR_FILE_PAGES) *
PAGE_SIZE);
seq_buf_printf(&s, "kernel_stack %llu\n",
(u64)memcg_page_state(memcg, MEMCG_KERNEL_STACK_KB) *
@ -3357,7 +3352,7 @@ static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
unsigned long val;
if (mem_cgroup_is_root(memcg)) {
val = memcg_page_state(memcg, MEMCG_CACHE) +
val = memcg_page_state(memcg, NR_FILE_PAGES) +
memcg_page_state(memcg, MEMCG_RSS);
if (swap)
val += memcg_page_state(memcg, MEMCG_SWAP);
@ -3828,7 +3823,7 @@ static int memcg_numa_stat_show(struct seq_file *m, void *v)
#endif /* CONFIG_NUMA */
static const unsigned int memcg1_stats[] = {
MEMCG_CACHE,
NR_FILE_PAGES,
MEMCG_RSS,
MEMCG_RSS_HUGE,
NR_SHMEM,
@ -5461,6 +5456,14 @@ static int mem_cgroup_move_account(struct page *page,
lock_page_memcg(page);
if (!PageAnon(page)) {
__mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages);
__mod_lruvec_state(to_vec, NR_FILE_PAGES, nr_pages);
if (PageSwapBacked(page)) {
__mod_lruvec_state(from_vec, NR_SHMEM, -nr_pages);
__mod_lruvec_state(to_vec, NR_SHMEM, nr_pages);
}
if (page_mapped(page)) {
__mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages);
__mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages);
@ -6673,10 +6676,8 @@ struct uncharge_gather {
unsigned long nr_pages;
unsigned long pgpgout;
unsigned long nr_anon;
unsigned long nr_file;
unsigned long nr_kmem;
unsigned long nr_huge;
unsigned long nr_shmem;
struct page *dummy_page;
};
@ -6700,9 +6701,7 @@ static void uncharge_batch(const struct uncharge_gather *ug)
local_irq_save(flags);
__mod_memcg_state(ug->memcg, MEMCG_RSS, -ug->nr_anon);
__mod_memcg_state(ug->memcg, MEMCG_CACHE, -ug->nr_file);
__mod_memcg_state(ug->memcg, MEMCG_RSS_HUGE, -ug->nr_huge);
__mod_memcg_state(ug->memcg, NR_SHMEM, -ug->nr_shmem);
__count_memcg_events(ug->memcg, PGPGOUT, ug->pgpgout);
__this_cpu_add(ug->memcg->vmstats_percpu->nr_page_events, ug->nr_pages);
memcg_check_events(ug->memcg, ug->dummy_page);
@ -6743,11 +6742,6 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug)
ug->nr_huge += nr_pages;
if (PageAnon(page))
ug->nr_anon += nr_pages;
else {
ug->nr_file += nr_pages;
if (PageSwapBacked(page))
ug->nr_shmem += nr_pages;
}
ug->pgpgout++;
} else {
ug->nr_kmem += nr_pages;

View File

@ -490,11 +490,18 @@ int migrate_page_move_mapping(struct address_space *mapping,
* are mapped to swap space.
*/
if (newzone != oldzone) {
__dec_node_state(oldzone->zone_pgdat, NR_FILE_PAGES);
__inc_node_state(newzone->zone_pgdat, NR_FILE_PAGES);
struct lruvec *old_lruvec, *new_lruvec;
struct mem_cgroup *memcg;
memcg = page_memcg(page);
old_lruvec = mem_cgroup_lruvec(memcg, oldzone->zone_pgdat);
new_lruvec = mem_cgroup_lruvec(memcg, newzone->zone_pgdat);
__dec_lruvec_state(old_lruvec, NR_FILE_PAGES);
__inc_lruvec_state(new_lruvec, NR_FILE_PAGES);
if (PageSwapBacked(page) && !PageSwapCache(page)) {
__dec_node_state(oldzone->zone_pgdat, NR_SHMEM);
__inc_node_state(newzone->zone_pgdat, NR_SHMEM);
__dec_lruvec_state(old_lruvec, NR_SHMEM);
__inc_lruvec_state(new_lruvec, NR_SHMEM);
}
if (dirty && mapping_cap_account_dirty(mapping)) {
__dec_node_state(oldzone->zone_pgdat, NR_FILE_DIRTY);

View File

@ -653,8 +653,8 @@ next:
__inc_node_page_state(page, NR_SHMEM_THPS);
}
mapping->nrpages += nr;
__mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, nr);
__mod_node_page_state(page_pgdat(page), NR_SHMEM, nr);
__mod_lruvec_page_state(page, NR_FILE_PAGES, nr);
__mod_lruvec_page_state(page, NR_SHMEM, nr);
unlock:
xas_unlock_irq(&xas);
} while (xas_nomem(&xas, gfp));
@ -685,8 +685,8 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap)
error = shmem_replace_entry(mapping, page->index, page, radswap);
page->mapping = NULL;
mapping->nrpages--;
__dec_node_page_state(page, NR_FILE_PAGES);
__dec_node_page_state(page, NR_SHMEM);
__dec_lruvec_page_state(page, NR_FILE_PAGES);
__dec_lruvec_page_state(page, NR_SHMEM);
xa_unlock_irq(&mapping->i_pages);
put_page(page);
BUG_ON(error);
@ -1593,8 +1593,9 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
xa_lock_irq(&swap_mapping->i_pages);
error = shmem_replace_entry(swap_mapping, swap_index, oldpage, newpage);
if (!error) {
__inc_node_page_state(newpage, NR_FILE_PAGES);
__dec_node_page_state(oldpage, NR_FILE_PAGES);
mem_cgroup_migrate(oldpage, newpage);
__inc_lruvec_page_state(newpage, NR_FILE_PAGES);
__dec_lruvec_page_state(oldpage, NR_FILE_PAGES);
}
xa_unlock_irq(&swap_mapping->i_pages);
@ -1606,7 +1607,6 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
*/
oldpage = newpage;
} else {
mem_cgroup_migrate(oldpage, newpage);
lru_cache_add_anon(newpage);
*pagep = newpage;
}