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Commit c9019e9b authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds
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mm: memcontrol: eliminate raw access to stat and event counters 

Replace all raw 'this_cpu_' modifications of the stat and event per-cpu
counters with API functions such as mod_memcg_state().

This makes the code easier to read, but is also in preparation for the
next patch, which changes the per-cpu implementation of those counters.

Link: http://lkml.kernel.org/r/20171103153336.24044-1-hannes@cmpxchg.org


Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarVladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2b9fceb3

include/linux/memcontrol.h

+20 −11
Original line number Diff line number Diff line
@@ -272,13 +272,6 @@ static inline bool mem_cgroup_disabled(void) 
	return !cgroup_subsys_enabled(memory_cgrp_subsys);

}



static inline void mem_cgroup_event(struct mem_cgroup *memcg,

				    enum memcg_event_item event)

{

	this_cpu_inc(memcg->stat->events[event]);

	cgroup_file_notify(&memcg->events_file);

}



bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg);



int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
@@ -627,15 +620,23 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, 
						gfp_t gfp_mask,

						unsigned long *total_scanned);



/* idx can be of type enum memcg_event_item or vm_event_item */

static inline void __count_memcg_events(struct mem_cgroup *memcg,

					int idx, unsigned long count)

{

	if (!mem_cgroup_disabled())

		__this_cpu_add(memcg->stat->events[idx], count);

}



/* idx can be of type enum memcg_event_item or vm_event_item */

static inline void count_memcg_events(struct mem_cgroup *memcg,

				      enum vm_event_item idx,

				      unsigned long count)

				      int idx, unsigned long count)

{

	if (!mem_cgroup_disabled())

		this_cpu_add(memcg->stat->events[idx], count);

}



/* idx can be of type enum memcg_stat_item or node_stat_item */

/* idx can be of type enum memcg_event_item or vm_event_item */

static inline void count_memcg_page_event(struct page *page,

					  int idx)

{
@@ -654,12 +655,20 @@ static inline void count_memcg_event_mm(struct mm_struct *mm, 
	rcu_read_lock();

	memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));

	if (likely(memcg)) {

		this_cpu_inc(memcg->stat->events[idx]);

		count_memcg_events(memcg, idx, 1);

		if (idx == OOM_KILL)

			cgroup_file_notify(&memcg->events_file);

	}

	rcu_read_unlock();

}



static inline void mem_cgroup_event(struct mem_cgroup *memcg,

				    enum memcg_event_item event)

{

	count_memcg_events(memcg, event, 1);

	cgroup_file_notify(&memcg->events_file);

}



#ifdef CONFIG_TRANSPARENT_HUGEPAGE

void mem_cgroup_split_huge_fixup(struct page *head);

#endif

mm/memcontrol.c

+25 −34
Original line number Diff line number Diff line
@@ -586,23 +586,23 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, 
	 * counted as CACHE even if it's on ANON LRU.

	 */

	if (PageAnon(page))

		__this_cpu_add(memcg->stat->count[MEMCG_RSS], nr_pages);

		__mod_memcg_state(memcg, MEMCG_RSS, nr_pages);

	else {

		__this_cpu_add(memcg->stat->count[MEMCG_CACHE], nr_pages);

		__mod_memcg_state(memcg, MEMCG_CACHE, nr_pages);

		if (PageSwapBacked(page))

			__this_cpu_add(memcg->stat->count[NR_SHMEM], nr_pages);

			__mod_memcg_state(memcg, NR_SHMEM, nr_pages);

	}



	if (compound) {

		VM_BUG_ON_PAGE(!PageTransHuge(page), page);

		__this_cpu_add(memcg->stat->count[MEMCG_RSS_HUGE], nr_pages);

		__mod_memcg_state(memcg, MEMCG_RSS_HUGE, nr_pages);

	}



	/* pagein of a big page is an event. So, ignore page size */

	if (nr_pages > 0)

		__this_cpu_inc(memcg->stat->events[PGPGIN]);

		__count_memcg_events(memcg, PGPGIN, 1);

	else {

		__this_cpu_inc(memcg->stat->events[PGPGOUT]);

		__count_memcg_events(memcg, PGPGOUT, 1);

		nr_pages = -nr_pages; /* for event */

	}
@@ -2415,18 +2415,11 @@ void mem_cgroup_split_huge_fixup(struct page *head) 
	for (i = 1; i < HPAGE_PMD_NR; i++)

		head[i].mem_cgroup = head->mem_cgroup;



	__this_cpu_sub(head->mem_cgroup->stat->count[MEMCG_RSS_HUGE],

		       HPAGE_PMD_NR);

	__mod_memcg_state(head->mem_cgroup, MEMCG_RSS_HUGE, -HPAGE_PMD_NR);

}

#endif /* CONFIG_TRANSPARENT_HUGEPAGE */



#ifdef CONFIG_MEMCG_SWAP

static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,

				       int nr_entries)

{

	this_cpu_add(memcg->stat->count[MEMCG_SWAP], nr_entries);

}



/**

 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.

 * @entry: swap entry to be moved
@@ -2450,8 +2443,8 @@ static int mem_cgroup_move_swap_account(swp_entry_t entry, 
	new_id = mem_cgroup_id(to);



	if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {

		mem_cgroup_swap_statistics(from, -1);

		mem_cgroup_swap_statistics(to, 1);

		mod_memcg_state(from, MEMCG_SWAP, -1);

		mod_memcg_state(to, MEMCG_SWAP, 1);

		return 0;

	}

	return -EINVAL;
@@ -4584,8 +4577,8 @@ static int mem_cgroup_move_account(struct page *page, 
	spin_lock_irqsave(&from->move_lock, flags);



	if (!anon && page_mapped(page)) {

		__this_cpu_sub(from->stat->count[NR_FILE_MAPPED], nr_pages);

		__this_cpu_add(to->stat->count[NR_FILE_MAPPED], nr_pages);

		__mod_memcg_state(from, NR_FILE_MAPPED, -nr_pages);

		__mod_memcg_state(to, NR_FILE_MAPPED, nr_pages);

	}



	/*
@@ -4597,16 +4590,14 @@ static int mem_cgroup_move_account(struct page *page, 
		struct address_space *mapping = page_mapping(page);



		if (mapping_cap_account_dirty(mapping)) {

			__this_cpu_sub(from->stat->count[NR_FILE_DIRTY],

				       nr_pages);

			__this_cpu_add(to->stat->count[NR_FILE_DIRTY],

				       nr_pages);

			__mod_memcg_state(from, NR_FILE_DIRTY, -nr_pages);

			__mod_memcg_state(to, NR_FILE_DIRTY, nr_pages);

		}

	}



	if (PageWriteback(page)) {

		__this_cpu_sub(from->stat->count[NR_WRITEBACK], nr_pages);

		__this_cpu_add(to->stat->count[NR_WRITEBACK], nr_pages);

		__mod_memcg_state(from, NR_WRITEBACK, -nr_pages);

		__mod_memcg_state(to, NR_WRITEBACK, nr_pages);

	}



	/*
@@ -5642,11 +5633,11 @@ static void uncharge_batch(const struct uncharge_gather *ug) 
	}



	local_irq_save(flags);

	__this_cpu_sub(ug->memcg->stat->count[MEMCG_RSS], ug->nr_anon);

	__this_cpu_sub(ug->memcg->stat->count[MEMCG_CACHE], ug->nr_file);

	__this_cpu_sub(ug->memcg->stat->count[MEMCG_RSS_HUGE], ug->nr_huge);

	__this_cpu_sub(ug->memcg->stat->count[NR_SHMEM], ug->nr_shmem);

	__this_cpu_add(ug->memcg->stat->events[PGPGOUT], ug->pgpgout);

	__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->stat->nr_page_events, nr_pages);

	memcg_check_events(ug->memcg, ug->dummy_page);

	local_irq_restore(flags);
@@ -5874,7 +5865,7 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) 
	if (in_softirq())

		gfp_mask = GFP_NOWAIT;



	this_cpu_add(memcg->stat->count[MEMCG_SOCK], nr_pages);

	mod_memcg_state(memcg, MEMCG_SOCK, nr_pages);



	if (try_charge(memcg, gfp_mask, nr_pages) == 0)

		return true;
@@ -5895,7 +5886,7 @@ void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) 
		return;

	}



	this_cpu_sub(memcg->stat->count[MEMCG_SOCK], nr_pages);

	mod_memcg_state(memcg, MEMCG_SOCK, -nr_pages);



	refill_stock(memcg, nr_pages);

}
@@ -6019,7 +6010,7 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) 
	oldid = swap_cgroup_record(entry, mem_cgroup_id(swap_memcg),

				   nr_entries);

	VM_BUG_ON_PAGE(oldid, page);

	mem_cgroup_swap_statistics(swap_memcg, nr_entries);

	mod_memcg_state(swap_memcg, MEMCG_SWAP, nr_entries);



	page->mem_cgroup = NULL;
@@ -6085,7 +6076,7 @@ int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) 
		mem_cgroup_id_get_many(memcg, nr_pages - 1);

	oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg), nr_pages);

	VM_BUG_ON_PAGE(oldid, page);

	mem_cgroup_swap_statistics(memcg, nr_pages);

	mod_memcg_state(memcg, MEMCG_SWAP, nr_pages);



	return 0;

}
@@ -6113,7 +6104,7 @@ void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) 
			else

				page_counter_uncharge(&memcg->memsw, nr_pages);

		}

		mem_cgroup_swap_statistics(memcg, -nr_pages);

		mod_memcg_state(memcg, MEMCG_SWAP, -nr_pages);

		mem_cgroup_id_put_many(memcg, nr_pages);

	}

	rcu_read_unlock();