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Commit e9f8974f authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds
Browse files

memcg: break out event counters from other stats 



For increasing and decreasing per-cpu cgroup usage counters it makes sense
to use signed types, as single per-cpu values might go negative during
updates.  But this is not the case for only-ever-increasing event
counters.

All the counters have been signed 64-bit so far, which was enough to count
events even with the sign bit wasted.

This patch:
- divides s64 counters into signed usage counters and unsigned
  monotonically increasing event counters.
- converts unsigned event counters into 'unsigned long' rather than
  'u64'.  This matches the type used by the /proc/vmstat event counters.

The next patch narrows the signed usage counters type (on 32-bit CPUs,
that is).

Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarGreg Thelen <gthelen@google.com>
Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: default avatarBalbir Singh <balbir@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7ec99d62

mm/memcontrol.c

+37 −12
Original line number Diff line number Diff line
@@ -93,19 +93,22 @@ enum mem_cgroup_stat_index { 
	MEM_CGROUP_STAT_CACHE, 	   /* # of pages charged as cache */

	MEM_CGROUP_STAT_RSS,	   /* # of pages charged as anon rss */

	MEM_CGROUP_STAT_FILE_MAPPED,  /* # of pages charged as file rss */

	MEM_CGROUP_STAT_PGPGIN_COUNT,	/* # of pages paged in */

	MEM_CGROUP_STAT_PGPGOUT_COUNT,	/* # of pages paged out */

	MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */

	MEM_CGROUP_STAT_DATA, /* end of data requires synchronization */

	/* incremented at every  pagein/pageout */

	MEM_CGROUP_EVENTS = MEM_CGROUP_STAT_DATA,

	MEM_CGROUP_ON_MOVE,	/* someone is moving account between groups */



	MEM_CGROUP_STAT_NSTATS,

};



enum mem_cgroup_events_index {

	MEM_CGROUP_EVENTS_PGPGIN,	/* # of pages paged in */

	MEM_CGROUP_EVENTS_PGPGOUT,	/* # of pages paged out */

	MEM_CGROUP_EVENTS_COUNT,	/* # of pages paged in/out */

	MEM_CGROUP_EVENTS_NSTATS,

};



struct mem_cgroup_stat_cpu {

	s64 count[MEM_CGROUP_STAT_NSTATS];

	unsigned long events[MEM_CGROUP_EVENTS_NSTATS];

};



/*
@@ -577,6 +580,22 @@ static void mem_cgroup_swap_statistics(struct mem_cgroup *mem, 
	this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_SWAPOUT], val);

}



static unsigned long mem_cgroup_read_events(struct mem_cgroup *mem,

					    enum mem_cgroup_events_index idx)

{

	unsigned long val = 0;

	int cpu;



	for_each_online_cpu(cpu)

		val += per_cpu(mem->stat->events[idx], cpu);

#ifdef CONFIG_HOTPLUG_CPU

	spin_lock(&mem->pcp_counter_lock);

	val += mem->nocpu_base.events[idx];

	spin_unlock(&mem->pcp_counter_lock);

#endif

	return val;

}



static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,

					 bool file, int nr_pages)

{
@@ -589,13 +608,13 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, 


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

	if (nr_pages > 0)

		__this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGIN_COUNT]);

		__this_cpu_inc(mem->stat->events[MEM_CGROUP_EVENTS_PGPGIN]);

	else {

		__this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGOUT_COUNT]);

		__this_cpu_inc(mem->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]);

		nr_pages = -nr_pages; /* for event */

	}



	__this_cpu_add(mem->stat->count[MEM_CGROUP_EVENTS], nr_pages);

	__this_cpu_add(mem->stat->events[MEM_CGROUP_EVENTS_COUNT], nr_pages);



	preempt_enable();

}
@@ -617,9 +636,9 @@ static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem, 


static bool __memcg_event_check(struct mem_cgroup *mem, int event_mask_shift)

{

	s64 val;

	unsigned long val;



	val = this_cpu_read(mem->stat->count[MEM_CGROUP_EVENTS]);

	val = this_cpu_read(mem->stat->events[MEM_CGROUP_EVENTS_COUNT]);



	return !(val & ((1 << event_mask_shift) - 1));

}
@@ -1773,6 +1792,12 @@ static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *mem, int cpu) 
		per_cpu(mem->stat->count[i], cpu) = 0;

		mem->nocpu_base.count[i] += x;

	}

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

		unsigned long x = per_cpu(mem->stat->events[i], cpu);



		per_cpu(mem->stat->events[i], cpu) = 0;

		mem->nocpu_base.events[i] += x;

	}

	/* need to clear ON_MOVE value, works as a kind of lock. */

	per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) = 0;

	spin_unlock(&mem->pcp_counter_lock);
@@ -3725,9 +3750,9 @@ mem_cgroup_get_local_stat(struct mem_cgroup *mem, struct mcs_total_stat *s) 
	s->stat[MCS_RSS] += val * PAGE_SIZE;

	val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_MAPPED);

	s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;

	val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGIN_COUNT);

	val = mem_cgroup_read_events(mem, MEM_CGROUP_EVENTS_PGPGIN);

	s->stat[MCS_PGPGIN] += val;

	val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGOUT_COUNT);

	val = mem_cgroup_read_events(mem, MEM_CGROUP_EVENTS_PGPGOUT);

	s->stat[MCS_PGPGOUT] += val;

	if (do_swap_account) {

		val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT);