mm: memcontrol: use root_mem_cgroup res_counter
Due to an old optimization to keep expensive res_counter changes at a minimum, the root_mem_cgroup res_counter is never charged; there is no limit at that level anyway, and any statistics can be generated on demand by summing up the counters of all other cgroups. However, with per-cpu charge caches, res_counter operations do not even show up in profiles anymore, so this optimization is no longer necessary. Remove it to simplify the code. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
692e7c45d9
commit
05b8430123
124
mm/memcontrol.c
124
mm/memcontrol.c
|
@ -2570,9 +2570,8 @@ static int mem_cgroup_try_charge(struct mem_cgroup *memcg,
|
|||
unsigned long nr_reclaimed;
|
||||
unsigned long flags = 0;
|
||||
unsigned long long size;
|
||||
int ret = 0;
|
||||
|
||||
if (mem_cgroup_is_root(memcg))
|
||||
goto done;
|
||||
retry:
|
||||
if (consume_stock(memcg, nr_pages))
|
||||
goto done;
|
||||
|
@ -2650,13 +2649,15 @@ nomem:
|
|||
if (!(gfp_mask & __GFP_NOFAIL))
|
||||
return -ENOMEM;
|
||||
bypass:
|
||||
return -EINTR;
|
||||
memcg = root_mem_cgroup;
|
||||
ret = -EINTR;
|
||||
goto retry;
|
||||
|
||||
done_restock:
|
||||
if (batch > nr_pages)
|
||||
refill_stock(memcg, batch - nr_pages);
|
||||
done:
|
||||
return 0;
|
||||
return ret;
|
||||
}
|
||||
|
||||
/**
|
||||
|
@ -2695,14 +2696,12 @@ static struct mem_cgroup *mem_cgroup_try_charge_mm(struct mm_struct *mm,
|
|||
static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg,
|
||||
unsigned int nr_pages)
|
||||
{
|
||||
if (!mem_cgroup_is_root(memcg)) {
|
||||
unsigned long bytes = nr_pages * PAGE_SIZE;
|
||||
|
||||
res_counter_uncharge(&memcg->res, bytes);
|
||||
if (do_swap_account)
|
||||
res_counter_uncharge(&memcg->memsw, bytes);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
|
||||
|
@ -2713,9 +2712,6 @@ static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg,
|
|||
{
|
||||
unsigned long bytes = nr_pages * PAGE_SIZE;
|
||||
|
||||
if (mem_cgroup_is_root(memcg))
|
||||
return;
|
||||
|
||||
res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes);
|
||||
if (do_swap_account)
|
||||
res_counter_uncharge_until(&memcg->memsw,
|
||||
|
@ -3943,7 +3939,7 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype,
|
|||
* replacement page, so leave it alone when phasing out the
|
||||
* page that is unused after the migration.
|
||||
*/
|
||||
if (!end_migration && !mem_cgroup_is_root(memcg))
|
||||
if (!end_migration)
|
||||
mem_cgroup_do_uncharge(memcg, nr_pages, ctype);
|
||||
|
||||
return memcg;
|
||||
|
@ -4076,7 +4072,6 @@ void mem_cgroup_uncharge_swap(swp_entry_t ent)
|
|||
* We uncharge this because swap is freed. This memcg can
|
||||
* be obsolete one. We avoid calling css_tryget_online().
|
||||
*/
|
||||
if (!mem_cgroup_is_root(memcg))
|
||||
res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
|
||||
mem_cgroup_swap_statistics(memcg, false);
|
||||
css_put(&memcg->css);
|
||||
|
@ -4767,78 +4762,24 @@ out:
|
|||
return retval;
|
||||
}
|
||||
|
||||
|
||||
static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg,
|
||||
enum mem_cgroup_stat_index idx)
|
||||
{
|
||||
struct mem_cgroup *iter;
|
||||
long val = 0;
|
||||
|
||||
/* Per-cpu values can be negative, use a signed accumulator */
|
||||
for_each_mem_cgroup_tree(iter, memcg)
|
||||
val += mem_cgroup_read_stat(iter, idx);
|
||||
|
||||
if (val < 0) /* race ? */
|
||||
val = 0;
|
||||
return val;
|
||||
}
|
||||
|
||||
static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
|
||||
{
|
||||
u64 val;
|
||||
|
||||
if (!mem_cgroup_is_root(memcg)) {
|
||||
if (!swap)
|
||||
return res_counter_read_u64(&memcg->res, RES_USAGE);
|
||||
else
|
||||
return res_counter_read_u64(&memcg->memsw, RES_USAGE);
|
||||
}
|
||||
|
||||
/*
|
||||
* Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
|
||||
* as well as in MEM_CGROUP_STAT_RSS_HUGE.
|
||||
*/
|
||||
val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE);
|
||||
val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS);
|
||||
|
||||
if (swap)
|
||||
val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAP);
|
||||
|
||||
return val << PAGE_SHIFT;
|
||||
}
|
||||
|
||||
static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
|
||||
struct cftype *cft)
|
||||
{
|
||||
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
||||
u64 val;
|
||||
int name;
|
||||
enum res_type type;
|
||||
|
||||
type = MEMFILE_TYPE(cft->private);
|
||||
name = MEMFILE_ATTR(cft->private);
|
||||
enum res_type type = MEMFILE_TYPE(cft->private);
|
||||
int name = MEMFILE_ATTR(cft->private);
|
||||
|
||||
switch (type) {
|
||||
case _MEM:
|
||||
if (name == RES_USAGE)
|
||||
val = mem_cgroup_usage(memcg, false);
|
||||
else
|
||||
val = res_counter_read_u64(&memcg->res, name);
|
||||
break;
|
||||
return res_counter_read_u64(&memcg->res, name);
|
||||
case _MEMSWAP:
|
||||
if (name == RES_USAGE)
|
||||
val = mem_cgroup_usage(memcg, true);
|
||||
else
|
||||
val = res_counter_read_u64(&memcg->memsw, name);
|
||||
break;
|
||||
return res_counter_read_u64(&memcg->memsw, name);
|
||||
case _KMEM:
|
||||
val = res_counter_read_u64(&memcg->kmem, name);
|
||||
return res_counter_read_u64(&memcg->kmem, name);
|
||||
break;
|
||||
default:
|
||||
BUG();
|
||||
}
|
||||
|
||||
return val;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_MEMCG_KMEM
|
||||
|
@ -5300,7 +5241,10 @@ static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
|
|||
if (!t)
|
||||
goto unlock;
|
||||
|
||||
usage = mem_cgroup_usage(memcg, swap);
|
||||
if (!swap)
|
||||
usage = res_counter_read_u64(&memcg->res, RES_USAGE);
|
||||
else
|
||||
usage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
|
||||
|
||||
/*
|
||||
* current_threshold points to threshold just below or equal to usage.
|
||||
|
@ -5396,15 +5340,15 @@ static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
|
|||
|
||||
mutex_lock(&memcg->thresholds_lock);
|
||||
|
||||
if (type == _MEM)
|
||||
if (type == _MEM) {
|
||||
thresholds = &memcg->thresholds;
|
||||
else if (type == _MEMSWAP)
|
||||
usage = res_counter_read_u64(&memcg->res, RES_USAGE);
|
||||
} else if (type == _MEMSWAP) {
|
||||
thresholds = &memcg->memsw_thresholds;
|
||||
else
|
||||
usage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
|
||||
} else
|
||||
BUG();
|
||||
|
||||
usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
|
||||
|
||||
/* Check if a threshold crossed before adding a new one */
|
||||
if (thresholds->primary)
|
||||
__mem_cgroup_threshold(memcg, type == _MEMSWAP);
|
||||
|
@ -5484,18 +5428,19 @@ static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
|
|||
int i, j, size;
|
||||
|
||||
mutex_lock(&memcg->thresholds_lock);
|
||||
if (type == _MEM)
|
||||
|
||||
if (type == _MEM) {
|
||||
thresholds = &memcg->thresholds;
|
||||
else if (type == _MEMSWAP)
|
||||
usage = res_counter_read_u64(&memcg->res, RES_USAGE);
|
||||
} else if (type == _MEMSWAP) {
|
||||
thresholds = &memcg->memsw_thresholds;
|
||||
else
|
||||
usage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
|
||||
} else
|
||||
BUG();
|
||||
|
||||
if (!thresholds->primary)
|
||||
goto unlock;
|
||||
|
||||
usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
|
||||
|
||||
/* Check if a threshold crossed before removing */
|
||||
__mem_cgroup_threshold(memcg, type == _MEMSWAP);
|
||||
|
||||
|
@ -6249,9 +6194,9 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
|
|||
* core guarantees its existence.
|
||||
*/
|
||||
} else {
|
||||
res_counter_init(&memcg->res, NULL);
|
||||
res_counter_init(&memcg->memsw, NULL);
|
||||
res_counter_init(&memcg->kmem, NULL);
|
||||
res_counter_init(&memcg->res, &root_mem_cgroup->res);
|
||||
res_counter_init(&memcg->memsw, &root_mem_cgroup->memsw);
|
||||
res_counter_init(&memcg->kmem, &root_mem_cgroup->kmem);
|
||||
/*
|
||||
* Deeper hierachy with use_hierarchy == false doesn't make
|
||||
* much sense so let cgroup subsystem know about this
|
||||
|
@ -6387,13 +6332,7 @@ static void mem_cgroup_css_reset(struct cgroup_subsys_state *css)
|
|||
/* Handlers for move charge at task migration. */
|
||||
static int mem_cgroup_do_precharge(unsigned long count)
|
||||
{
|
||||
int ret = 0;
|
||||
|
||||
if (mem_cgroup_is_root(mc.to)) {
|
||||
mc.precharge += count;
|
||||
/* we don't need css_get for root */
|
||||
return ret;
|
||||
}
|
||||
int ret;
|
||||
|
||||
/* Try a single bulk charge without reclaim first */
|
||||
ret = mem_cgroup_try_charge(mc.to, GFP_KERNEL & ~__GFP_WAIT, count);
|
||||
|
@ -6700,21 +6639,18 @@ static void __mem_cgroup_clear_mc(void)
|
|||
/* we must fixup refcnts and charges */
|
||||
if (mc.moved_swap) {
|
||||
/* uncharge swap account from the old cgroup */
|
||||
if (!mem_cgroup_is_root(mc.from))
|
||||
res_counter_uncharge(&mc.from->memsw,
|
||||
PAGE_SIZE * mc.moved_swap);
|
||||
|
||||
for (i = 0; i < mc.moved_swap; i++)
|
||||
css_put(&mc.from->css);
|
||||
|
||||
if (!mem_cgroup_is_root(mc.to)) {
|
||||
/*
|
||||
* we charged both to->res and to->memsw, so we should
|
||||
* uncharge to->res.
|
||||
*/
|
||||
res_counter_uncharge(&mc.to->res,
|
||||
PAGE_SIZE * mc.moved_swap);
|
||||
}
|
||||
/* we've already done css_get(mc.to) */
|
||||
mc.moved_swap = 0;
|
||||
}
|
||||
|
|
Loading…
Reference in New Issue