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Commit 587d9f72 authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds
Browse files

mm: memcontrol: basic memory statistics in cgroup2 memory controller 



Provide a cgroup2 memory.stat that provides statistics on LRU memory
and fault event counters. More consumers and breakdowns will follow.

Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarVladimir Davydov <vdavydov@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 44b7a8d3

Documentation/cgroup-v2.txt

+56 −0
Original line number Diff line number Diff line
@@ -819,6 +819,62 @@ PAGE_SIZE multiple when read back. 
		the cgroup.  This may not exactly match the number of

		processes killed but should generally be close.



  memory.stat



	A read-only flat-keyed file which exists on non-root cgroups.



	This breaks down the cgroup's memory footprint into different

	types of memory, type-specific details, and other information

	on the state and past events of the memory management system.



	All memory amounts are in bytes.



	The entries are ordered to be human readable, and new entries

	can show up in the middle. Don't rely on items remaining in a

	fixed position; use the keys to look up specific values!



	  anon



		Amount of memory used in anonymous mappings such as

		brk(), sbrk(), and mmap(MAP_ANONYMOUS)



	  file



		Amount of memory used to cache filesystem data,

		including tmpfs and shared memory.



	  file_mapped



		Amount of cached filesystem data mapped with mmap()



	  file_dirty



		Amount of cached filesystem data that was modified but

		not yet written back to disk



	  file_writeback



		Amount of cached filesystem data that was modified and

		is currently being written back to disk



	  inactive_anon

	  active_anon

	  inactive_file

	  active_file

	  unevictable



		Amount of memory, swap-backed and filesystem-backed,

		on the internal memory management lists used by the

		page reclaim algorithm



	  pgfault



		Total number of page faults incurred



	  pgmajfault



		Number of major page faults incurred



  memory.swap.current



	A read-only single value file which exists on non-root

mm/memcontrol.c

+68 −0
Original line number Diff line number Diff line
@@ -2767,6 +2767,18 @@ static unsigned long tree_stat(struct mem_cgroup *memcg, 
	return val;

}



static unsigned long tree_events(struct mem_cgroup *memcg,

				 enum mem_cgroup_events_index idx)

{

	struct mem_cgroup *iter;

	unsigned long val = 0;



	for_each_mem_cgroup_tree(iter, memcg)

		val += mem_cgroup_read_events(iter, idx);



	return val;

}



static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)

{

	unsigned long val;
@@ -5096,6 +5108,57 @@ static int memory_events_show(struct seq_file *m, void *v) 
	return 0;

}



static int memory_stat_show(struct seq_file *m, void *v)

{

	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));

	int i;



	/*

	 * Provide statistics on the state of the memory subsystem as

	 * well as cumulative event counters that show past behavior.

	 *

	 * This list is ordered following a combination of these gradients:

	 * 1) generic big picture -> specifics and details

	 * 2) reflecting userspace activity -> reflecting kernel heuristics

	 *

	 * Current memory state:

	 */



	seq_printf(m, "anon %llu\n",

		   (u64)tree_stat(memcg, MEM_CGROUP_STAT_RSS) * PAGE_SIZE);

	seq_printf(m, "file %llu\n",

		   (u64)tree_stat(memcg, MEM_CGROUP_STAT_CACHE) * PAGE_SIZE);



	seq_printf(m, "file_mapped %llu\n",

		   (u64)tree_stat(memcg, MEM_CGROUP_STAT_FILE_MAPPED) *

		   PAGE_SIZE);

	seq_printf(m, "file_dirty %llu\n",

		   (u64)tree_stat(memcg, MEM_CGROUP_STAT_DIRTY) *

		   PAGE_SIZE);

	seq_printf(m, "file_writeback %llu\n",

		   (u64)tree_stat(memcg, MEM_CGROUP_STAT_WRITEBACK) *

		   PAGE_SIZE);



	for (i = 0; i < NR_LRU_LISTS; i++) {

		struct mem_cgroup *mi;

		unsigned long val = 0;



		for_each_mem_cgroup_tree(mi, memcg)

			val += mem_cgroup_nr_lru_pages(mi, BIT(i));

		seq_printf(m, "%s %llu\n",

			   mem_cgroup_lru_names[i], (u64)val * PAGE_SIZE);

	}



	/* Accumulated memory events */



	seq_printf(m, "pgfault %lu\n",

		   tree_events(memcg, MEM_CGROUP_EVENTS_PGFAULT));

	seq_printf(m, "pgmajfault %lu\n",

		   tree_events(memcg, MEM_CGROUP_EVENTS_PGMAJFAULT));



	return 0;

}



static struct cftype memory_files[] = {

	{

		.name = "current",
@@ -5126,6 +5189,11 @@ static struct cftype memory_files[] = { 
		.file_offset = offsetof(struct mem_cgroup, events_file),

		.seq_show = memory_events_show,

	},

	{

		.name = "stat",

		.flags = CFTYPE_NOT_ON_ROOT,

		.seq_show = memory_stat_show,

	},

	{ }	/* terminate */

};