linux-stable/mm/hugetlb_cgroup.c
Miaohe Lin d85aecf284 hugetlb_cgroup: fix imbalanced css_get and css_put pair for shared mappings
The current implementation of hugetlb_cgroup for shared mappings could
have different behavior.  Consider the following two scenarios:

 1.Assume initial css reference count of hugetlb_cgroup is 1:
  1.1 Call hugetlb_reserve_pages with from = 1, to = 2. So css reference
      count is 2 associated with 1 file_region.
  1.2 Call hugetlb_reserve_pages with from = 2, to = 3. So css reference
      count is 3 associated with 2 file_region.
  1.3 coalesce_file_region will coalesce these two file_regions into
      one. So css reference count is 3 associated with 1 file_region
      now.

 2.Assume initial css reference count of hugetlb_cgroup is 1 again:
  2.1 Call hugetlb_reserve_pages with from = 1, to = 3. So css reference
      count is 2 associated with 1 file_region.

Therefore, we might have one file_region while holding one or more css
reference counts. This inconsistency could lead to imbalanced css_get()
and css_put() pair. If we do css_put one by one (i.g. hole punch case),
scenario 2 would put one more css reference. If we do css_put all
together (i.g. truncate case), scenario 1 will leak one css reference.

The imbalanced css_get() and css_put() pair would result in a non-zero
reference when we try to destroy the hugetlb cgroup. The hugetlb cgroup
directory is removed __but__ associated resource is not freed. This
might result in OOM or can not create a new hugetlb cgroup in a busy
workload ultimately.

In order to fix this, we have to make sure that one file_region must
hold exactly one css reference. So in coalesce_file_region case, we
should release one css reference before coalescence. Also only put css
reference when the entire file_region is removed.

The last thing to note is that the caller of region_add() will only hold
one reference to h_cg->css for the whole contiguous reservation region.
But this area might be scattered when there are already some
file_regions reside in it. As a result, many file_regions may share only
one h_cg->css reference. In order to ensure that one file_region must
hold exactly one css reference, we should do css_get() for each
file_region and release the reference held by caller when they are done.

[linmiaohe@huawei.com: fix imbalanced css_get and css_put pair for shared mappings]
  Link: https://lkml.kernel.org/r/20210316023002.53921-1-linmiaohe@huawei.com

Link: https://lkml.kernel.org/r/20210301120540.37076-1-linmiaohe@huawei.com
Fixes: 075a61d07a ("hugetlb_cgroup: add accounting for shared mappings")
Reported-by: kernel test robot <lkp@intel.com> (auto build test ERROR)
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Wanpeng Li <liwp.linux@gmail.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-03-25 09:22:55 -07:00

812 lines
22 KiB
C

/*
*
* Copyright IBM Corporation, 2012
* Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
*
* Cgroup v2
* Copyright (C) 2019 Red Hat, Inc.
* Author: Giuseppe Scrivano <gscrivan@redhat.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2.1 of the GNU Lesser General Public License
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
*/
#include <linux/cgroup.h>
#include <linux/page_counter.h>
#include <linux/slab.h>
#include <linux/hugetlb.h>
#include <linux/hugetlb_cgroup.h>
#define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
#define MEMFILE_IDX(val) (((val) >> 16) & 0xffff)
#define MEMFILE_ATTR(val) ((val) & 0xffff)
#define hugetlb_cgroup_from_counter(counter, idx) \
container_of(counter, struct hugetlb_cgroup, hugepage[idx])
static struct hugetlb_cgroup *root_h_cgroup __read_mostly;
static inline struct page_counter *
__hugetlb_cgroup_counter_from_cgroup(struct hugetlb_cgroup *h_cg, int idx,
bool rsvd)
{
if (rsvd)
return &h_cg->rsvd_hugepage[idx];
return &h_cg->hugepage[idx];
}
static inline struct page_counter *
hugetlb_cgroup_counter_from_cgroup(struct hugetlb_cgroup *h_cg, int idx)
{
return __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, false);
}
static inline struct page_counter *
hugetlb_cgroup_counter_from_cgroup_rsvd(struct hugetlb_cgroup *h_cg, int idx)
{
return __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, true);
}
static inline
struct hugetlb_cgroup *hugetlb_cgroup_from_css(struct cgroup_subsys_state *s)
{
return s ? container_of(s, struct hugetlb_cgroup, css) : NULL;
}
static inline
struct hugetlb_cgroup *hugetlb_cgroup_from_task(struct task_struct *task)
{
return hugetlb_cgroup_from_css(task_css(task, hugetlb_cgrp_id));
}
static inline bool hugetlb_cgroup_is_root(struct hugetlb_cgroup *h_cg)
{
return (h_cg == root_h_cgroup);
}
static inline struct hugetlb_cgroup *
parent_hugetlb_cgroup(struct hugetlb_cgroup *h_cg)
{
return hugetlb_cgroup_from_css(h_cg->css.parent);
}
static inline bool hugetlb_cgroup_have_usage(struct hugetlb_cgroup *h_cg)
{
int idx;
for (idx = 0; idx < hugetlb_max_hstate; idx++) {
if (page_counter_read(
hugetlb_cgroup_counter_from_cgroup(h_cg, idx)))
return true;
}
return false;
}
static void hugetlb_cgroup_init(struct hugetlb_cgroup *h_cgroup,
struct hugetlb_cgroup *parent_h_cgroup)
{
int idx;
for (idx = 0; idx < HUGE_MAX_HSTATE; idx++) {
struct page_counter *fault_parent = NULL;
struct page_counter *rsvd_parent = NULL;
unsigned long limit;
int ret;
if (parent_h_cgroup) {
fault_parent = hugetlb_cgroup_counter_from_cgroup(
parent_h_cgroup, idx);
rsvd_parent = hugetlb_cgroup_counter_from_cgroup_rsvd(
parent_h_cgroup, idx);
}
page_counter_init(hugetlb_cgroup_counter_from_cgroup(h_cgroup,
idx),
fault_parent);
page_counter_init(
hugetlb_cgroup_counter_from_cgroup_rsvd(h_cgroup, idx),
rsvd_parent);
limit = round_down(PAGE_COUNTER_MAX,
pages_per_huge_page(&hstates[idx]));
ret = page_counter_set_max(
hugetlb_cgroup_counter_from_cgroup(h_cgroup, idx),
limit);
VM_BUG_ON(ret);
ret = page_counter_set_max(
hugetlb_cgroup_counter_from_cgroup_rsvd(h_cgroup, idx),
limit);
VM_BUG_ON(ret);
}
}
static struct cgroup_subsys_state *
hugetlb_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct hugetlb_cgroup *parent_h_cgroup = hugetlb_cgroup_from_css(parent_css);
struct hugetlb_cgroup *h_cgroup;
h_cgroup = kzalloc(sizeof(*h_cgroup), GFP_KERNEL);
if (!h_cgroup)
return ERR_PTR(-ENOMEM);
if (!parent_h_cgroup)
root_h_cgroup = h_cgroup;
hugetlb_cgroup_init(h_cgroup, parent_h_cgroup);
return &h_cgroup->css;
}
static void hugetlb_cgroup_css_free(struct cgroup_subsys_state *css)
{
struct hugetlb_cgroup *h_cgroup;
h_cgroup = hugetlb_cgroup_from_css(css);
kfree(h_cgroup);
}
/*
* Should be called with hugetlb_lock held.
* Since we are holding hugetlb_lock, pages cannot get moved from
* active list or uncharged from the cgroup, So no need to get
* page reference and test for page active here. This function
* cannot fail.
*/
static void hugetlb_cgroup_move_parent(int idx, struct hugetlb_cgroup *h_cg,
struct page *page)
{
unsigned int nr_pages;
struct page_counter *counter;
struct hugetlb_cgroup *page_hcg;
struct hugetlb_cgroup *parent = parent_hugetlb_cgroup(h_cg);
page_hcg = hugetlb_cgroup_from_page(page);
/*
* We can have pages in active list without any cgroup
* ie, hugepage with less than 3 pages. We can safely
* ignore those pages.
*/
if (!page_hcg || page_hcg != h_cg)
goto out;
nr_pages = compound_nr(page);
if (!parent) {
parent = root_h_cgroup;
/* root has no limit */
page_counter_charge(&parent->hugepage[idx], nr_pages);
}
counter = &h_cg->hugepage[idx];
/* Take the pages off the local counter */
page_counter_cancel(counter, nr_pages);
set_hugetlb_cgroup(page, parent);
out:
return;
}
/*
* Force the hugetlb cgroup to empty the hugetlb resources by moving them to
* the parent cgroup.
*/
static void hugetlb_cgroup_css_offline(struct cgroup_subsys_state *css)
{
struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css);
struct hstate *h;
struct page *page;
int idx;
do {
idx = 0;
for_each_hstate(h) {
spin_lock(&hugetlb_lock);
list_for_each_entry(page, &h->hugepage_activelist, lru)
hugetlb_cgroup_move_parent(idx, h_cg, page);
spin_unlock(&hugetlb_lock);
idx++;
}
cond_resched();
} while (hugetlb_cgroup_have_usage(h_cg));
}
static inline void hugetlb_event(struct hugetlb_cgroup *hugetlb, int idx,
enum hugetlb_memory_event event)
{
atomic_long_inc(&hugetlb->events_local[idx][event]);
cgroup_file_notify(&hugetlb->events_local_file[idx]);
do {
atomic_long_inc(&hugetlb->events[idx][event]);
cgroup_file_notify(&hugetlb->events_file[idx]);
} while ((hugetlb = parent_hugetlb_cgroup(hugetlb)) &&
!hugetlb_cgroup_is_root(hugetlb));
}
static int __hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
struct hugetlb_cgroup **ptr,
bool rsvd)
{
int ret = 0;
struct page_counter *counter;
struct hugetlb_cgroup *h_cg = NULL;
if (hugetlb_cgroup_disabled())
goto done;
/*
* We don't charge any cgroup if the compound page have less
* than 3 pages.
*/
if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER)
goto done;
again:
rcu_read_lock();
h_cg = hugetlb_cgroup_from_task(current);
if (!css_tryget(&h_cg->css)) {
rcu_read_unlock();
goto again;
}
rcu_read_unlock();
if (!page_counter_try_charge(
__hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd),
nr_pages, &counter)) {
ret = -ENOMEM;
hugetlb_event(h_cg, idx, HUGETLB_MAX);
css_put(&h_cg->css);
goto done;
}
/* Reservations take a reference to the css because they do not get
* reparented.
*/
if (!rsvd)
css_put(&h_cg->css);
done:
*ptr = h_cg;
return ret;
}
int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
struct hugetlb_cgroup **ptr)
{
return __hugetlb_cgroup_charge_cgroup(idx, nr_pages, ptr, false);
}
int hugetlb_cgroup_charge_cgroup_rsvd(int idx, unsigned long nr_pages,
struct hugetlb_cgroup **ptr)
{
return __hugetlb_cgroup_charge_cgroup(idx, nr_pages, ptr, true);
}
/* Should be called with hugetlb_lock held */
static void __hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
struct hugetlb_cgroup *h_cg,
struct page *page, bool rsvd)
{
if (hugetlb_cgroup_disabled() || !h_cg)
return;
__set_hugetlb_cgroup(page, h_cg, rsvd);
return;
}
void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
struct hugetlb_cgroup *h_cg,
struct page *page)
{
__hugetlb_cgroup_commit_charge(idx, nr_pages, h_cg, page, false);
}
void hugetlb_cgroup_commit_charge_rsvd(int idx, unsigned long nr_pages,
struct hugetlb_cgroup *h_cg,
struct page *page)
{
__hugetlb_cgroup_commit_charge(idx, nr_pages, h_cg, page, true);
}
/*
* Should be called with hugetlb_lock held
*/
static void __hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages,
struct page *page, bool rsvd)
{
struct hugetlb_cgroup *h_cg;
if (hugetlb_cgroup_disabled())
return;
lockdep_assert_held(&hugetlb_lock);
h_cg = __hugetlb_cgroup_from_page(page, rsvd);
if (unlikely(!h_cg))
return;
__set_hugetlb_cgroup(page, NULL, rsvd);
page_counter_uncharge(__hugetlb_cgroup_counter_from_cgroup(h_cg, idx,
rsvd),
nr_pages);
if (rsvd)
css_put(&h_cg->css);
return;
}
void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages,
struct page *page)
{
__hugetlb_cgroup_uncharge_page(idx, nr_pages, page, false);
}
void hugetlb_cgroup_uncharge_page_rsvd(int idx, unsigned long nr_pages,
struct page *page)
{
__hugetlb_cgroup_uncharge_page(idx, nr_pages, page, true);
}
static void __hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
struct hugetlb_cgroup *h_cg,
bool rsvd)
{
if (hugetlb_cgroup_disabled() || !h_cg)
return;
if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER)
return;
page_counter_uncharge(__hugetlb_cgroup_counter_from_cgroup(h_cg, idx,
rsvd),
nr_pages);
if (rsvd)
css_put(&h_cg->css);
}
void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
struct hugetlb_cgroup *h_cg)
{
__hugetlb_cgroup_uncharge_cgroup(idx, nr_pages, h_cg, false);
}
void hugetlb_cgroup_uncharge_cgroup_rsvd(int idx, unsigned long nr_pages,
struct hugetlb_cgroup *h_cg)
{
__hugetlb_cgroup_uncharge_cgroup(idx, nr_pages, h_cg, true);
}
void hugetlb_cgroup_uncharge_counter(struct resv_map *resv, unsigned long start,
unsigned long end)
{
if (hugetlb_cgroup_disabled() || !resv || !resv->reservation_counter ||
!resv->css)
return;
page_counter_uncharge(resv->reservation_counter,
(end - start) * resv->pages_per_hpage);
css_put(resv->css);
}
void hugetlb_cgroup_uncharge_file_region(struct resv_map *resv,
struct file_region *rg,
unsigned long nr_pages,
bool region_del)
{
if (hugetlb_cgroup_disabled() || !resv || !rg || !nr_pages)
return;
if (rg->reservation_counter && resv->pages_per_hpage && nr_pages > 0 &&
!resv->reservation_counter) {
page_counter_uncharge(rg->reservation_counter,
nr_pages * resv->pages_per_hpage);
/*
* Only do css_put(rg->css) when we delete the entire region
* because one file_region must hold exactly one css reference.
*/
if (region_del)
css_put(rg->css);
}
}
enum {
RES_USAGE,
RES_RSVD_USAGE,
RES_LIMIT,
RES_RSVD_LIMIT,
RES_MAX_USAGE,
RES_RSVD_MAX_USAGE,
RES_FAILCNT,
RES_RSVD_FAILCNT,
};
static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css,
struct cftype *cft)
{
struct page_counter *counter;
struct page_counter *rsvd_counter;
struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css);
counter = &h_cg->hugepage[MEMFILE_IDX(cft->private)];
rsvd_counter = &h_cg->rsvd_hugepage[MEMFILE_IDX(cft->private)];
switch (MEMFILE_ATTR(cft->private)) {
case RES_USAGE:
return (u64)page_counter_read(counter) * PAGE_SIZE;
case RES_RSVD_USAGE:
return (u64)page_counter_read(rsvd_counter) * PAGE_SIZE;
case RES_LIMIT:
return (u64)counter->max * PAGE_SIZE;
case RES_RSVD_LIMIT:
return (u64)rsvd_counter->max * PAGE_SIZE;
case RES_MAX_USAGE:
return (u64)counter->watermark * PAGE_SIZE;
case RES_RSVD_MAX_USAGE:
return (u64)rsvd_counter->watermark * PAGE_SIZE;
case RES_FAILCNT:
return counter->failcnt;
case RES_RSVD_FAILCNT:
return rsvd_counter->failcnt;
default:
BUG();
}
}
static int hugetlb_cgroup_read_u64_max(struct seq_file *seq, void *v)
{
int idx;
u64 val;
struct cftype *cft = seq_cft(seq);
unsigned long limit;
struct page_counter *counter;
struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(seq_css(seq));
idx = MEMFILE_IDX(cft->private);
counter = &h_cg->hugepage[idx];
limit = round_down(PAGE_COUNTER_MAX,
pages_per_huge_page(&hstates[idx]));
switch (MEMFILE_ATTR(cft->private)) {
case RES_RSVD_USAGE:
counter = &h_cg->rsvd_hugepage[idx];
fallthrough;
case RES_USAGE:
val = (u64)page_counter_read(counter);
seq_printf(seq, "%llu\n", val * PAGE_SIZE);
break;
case RES_RSVD_LIMIT:
counter = &h_cg->rsvd_hugepage[idx];
fallthrough;
case RES_LIMIT:
val = (u64)counter->max;
if (val == limit)
seq_puts(seq, "max\n");
else
seq_printf(seq, "%llu\n", val * PAGE_SIZE);
break;
default:
BUG();
}
return 0;
}
static DEFINE_MUTEX(hugetlb_limit_mutex);
static ssize_t hugetlb_cgroup_write(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off,
const char *max)
{
int ret, idx;
unsigned long nr_pages;
struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of));
bool rsvd = false;
if (hugetlb_cgroup_is_root(h_cg)) /* Can't set limit on root */
return -EINVAL;
buf = strstrip(buf);
ret = page_counter_memparse(buf, max, &nr_pages);
if (ret)
return ret;
idx = MEMFILE_IDX(of_cft(of)->private);
nr_pages = round_down(nr_pages, pages_per_huge_page(&hstates[idx]));
switch (MEMFILE_ATTR(of_cft(of)->private)) {
case RES_RSVD_LIMIT:
rsvd = true;
fallthrough;
case RES_LIMIT:
mutex_lock(&hugetlb_limit_mutex);
ret = page_counter_set_max(
__hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd),
nr_pages);
mutex_unlock(&hugetlb_limit_mutex);
break;
default:
ret = -EINVAL;
break;
}
return ret ?: nbytes;
}
static ssize_t hugetlb_cgroup_write_legacy(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
return hugetlb_cgroup_write(of, buf, nbytes, off, "-1");
}
static ssize_t hugetlb_cgroup_write_dfl(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
return hugetlb_cgroup_write(of, buf, nbytes, off, "max");
}
static ssize_t hugetlb_cgroup_reset(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
int ret = 0;
struct page_counter *counter, *rsvd_counter;
struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of));
counter = &h_cg->hugepage[MEMFILE_IDX(of_cft(of)->private)];
rsvd_counter = &h_cg->rsvd_hugepage[MEMFILE_IDX(of_cft(of)->private)];
switch (MEMFILE_ATTR(of_cft(of)->private)) {
case RES_MAX_USAGE:
page_counter_reset_watermark(counter);
break;
case RES_RSVD_MAX_USAGE:
page_counter_reset_watermark(rsvd_counter);
break;
case RES_FAILCNT:
counter->failcnt = 0;
break;
case RES_RSVD_FAILCNT:
rsvd_counter->failcnt = 0;
break;
default:
ret = -EINVAL;
break;
}
return ret ?: nbytes;
}
static char *mem_fmt(char *buf, int size, unsigned long hsize)
{
if (hsize >= (1UL << 30))
snprintf(buf, size, "%luGB", hsize >> 30);
else if (hsize >= (1UL << 20))
snprintf(buf, size, "%luMB", hsize >> 20);
else
snprintf(buf, size, "%luKB", hsize >> 10);
return buf;
}
static int __hugetlb_events_show(struct seq_file *seq, bool local)
{
int idx;
long max;
struct cftype *cft = seq_cft(seq);
struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(seq_css(seq));
idx = MEMFILE_IDX(cft->private);
if (local)
max = atomic_long_read(&h_cg->events_local[idx][HUGETLB_MAX]);
else
max = atomic_long_read(&h_cg->events[idx][HUGETLB_MAX]);
seq_printf(seq, "max %lu\n", max);
return 0;
}
static int hugetlb_events_show(struct seq_file *seq, void *v)
{
return __hugetlb_events_show(seq, false);
}
static int hugetlb_events_local_show(struct seq_file *seq, void *v)
{
return __hugetlb_events_show(seq, true);
}
static void __init __hugetlb_cgroup_file_dfl_init(int idx)
{
char buf[32];
struct cftype *cft;
struct hstate *h = &hstates[idx];
/* format the size */
mem_fmt(buf, sizeof(buf), huge_page_size(h));
/* Add the limit file */
cft = &h->cgroup_files_dfl[0];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.max", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT);
cft->seq_show = hugetlb_cgroup_read_u64_max;
cft->write = hugetlb_cgroup_write_dfl;
cft->flags = CFTYPE_NOT_ON_ROOT;
/* Add the reservation limit file */
cft = &h->cgroup_files_dfl[1];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.max", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_LIMIT);
cft->seq_show = hugetlb_cgroup_read_u64_max;
cft->write = hugetlb_cgroup_write_dfl;
cft->flags = CFTYPE_NOT_ON_ROOT;
/* Add the current usage file */
cft = &h->cgroup_files_dfl[2];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.current", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_USAGE);
cft->seq_show = hugetlb_cgroup_read_u64_max;
cft->flags = CFTYPE_NOT_ON_ROOT;
/* Add the current reservation usage file */
cft = &h->cgroup_files_dfl[3];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.current", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_USAGE);
cft->seq_show = hugetlb_cgroup_read_u64_max;
cft->flags = CFTYPE_NOT_ON_ROOT;
/* Add the events file */
cft = &h->cgroup_files_dfl[4];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.events", buf);
cft->private = MEMFILE_PRIVATE(idx, 0);
cft->seq_show = hugetlb_events_show;
cft->file_offset = offsetof(struct hugetlb_cgroup, events_file[idx]);
cft->flags = CFTYPE_NOT_ON_ROOT;
/* Add the events.local file */
cft = &h->cgroup_files_dfl[5];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.events.local", buf);
cft->private = MEMFILE_PRIVATE(idx, 0);
cft->seq_show = hugetlb_events_local_show;
cft->file_offset = offsetof(struct hugetlb_cgroup,
events_local_file[idx]);
cft->flags = CFTYPE_NOT_ON_ROOT;
/* NULL terminate the last cft */
cft = &h->cgroup_files_dfl[6];
memset(cft, 0, sizeof(*cft));
WARN_ON(cgroup_add_dfl_cftypes(&hugetlb_cgrp_subsys,
h->cgroup_files_dfl));
}
static void __init __hugetlb_cgroup_file_legacy_init(int idx)
{
char buf[32];
struct cftype *cft;
struct hstate *h = &hstates[idx];
/* format the size */
mem_fmt(buf, sizeof(buf), huge_page_size(h));
/* Add the limit file */
cft = &h->cgroup_files_legacy[0];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.limit_in_bytes", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT);
cft->read_u64 = hugetlb_cgroup_read_u64;
cft->write = hugetlb_cgroup_write_legacy;
/* Add the reservation limit file */
cft = &h->cgroup_files_legacy[1];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.limit_in_bytes", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_LIMIT);
cft->read_u64 = hugetlb_cgroup_read_u64;
cft->write = hugetlb_cgroup_write_legacy;
/* Add the usage file */
cft = &h->cgroup_files_legacy[2];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.usage_in_bytes", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_USAGE);
cft->read_u64 = hugetlb_cgroup_read_u64;
/* Add the reservation usage file */
cft = &h->cgroup_files_legacy[3];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.usage_in_bytes", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_USAGE);
cft->read_u64 = hugetlb_cgroup_read_u64;
/* Add the MAX usage file */
cft = &h->cgroup_files_legacy[4];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.max_usage_in_bytes", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_MAX_USAGE);
cft->write = hugetlb_cgroup_reset;
cft->read_u64 = hugetlb_cgroup_read_u64;
/* Add the MAX reservation usage file */
cft = &h->cgroup_files_legacy[5];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.max_usage_in_bytes", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_MAX_USAGE);
cft->write = hugetlb_cgroup_reset;
cft->read_u64 = hugetlb_cgroup_read_u64;
/* Add the failcntfile */
cft = &h->cgroup_files_legacy[6];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.failcnt", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_FAILCNT);
cft->write = hugetlb_cgroup_reset;
cft->read_u64 = hugetlb_cgroup_read_u64;
/* Add the reservation failcntfile */
cft = &h->cgroup_files_legacy[7];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.failcnt", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_FAILCNT);
cft->write = hugetlb_cgroup_reset;
cft->read_u64 = hugetlb_cgroup_read_u64;
/* NULL terminate the last cft */
cft = &h->cgroup_files_legacy[8];
memset(cft, 0, sizeof(*cft));
WARN_ON(cgroup_add_legacy_cftypes(&hugetlb_cgrp_subsys,
h->cgroup_files_legacy));
}
static void __init __hugetlb_cgroup_file_init(int idx)
{
__hugetlb_cgroup_file_dfl_init(idx);
__hugetlb_cgroup_file_legacy_init(idx);
}
void __init hugetlb_cgroup_file_init(void)
{
struct hstate *h;
for_each_hstate(h) {
/*
* Add cgroup control files only if the huge page consists
* of more than two normal pages. This is because we use
* page[2].private for storing cgroup details.
*/
if (huge_page_order(h) >= HUGETLB_CGROUP_MIN_ORDER)
__hugetlb_cgroup_file_init(hstate_index(h));
}
}
/*
* hugetlb_lock will make sure a parallel cgroup rmdir won't happen
* when we migrate hugepages
*/
void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage)
{
struct hugetlb_cgroup *h_cg;
struct hugetlb_cgroup *h_cg_rsvd;
struct hstate *h = page_hstate(oldhpage);
if (hugetlb_cgroup_disabled())
return;
VM_BUG_ON_PAGE(!PageHuge(oldhpage), oldhpage);
spin_lock(&hugetlb_lock);
h_cg = hugetlb_cgroup_from_page(oldhpage);
h_cg_rsvd = hugetlb_cgroup_from_page_rsvd(oldhpage);
set_hugetlb_cgroup(oldhpage, NULL);
set_hugetlb_cgroup_rsvd(oldhpage, NULL);
/* move the h_cg details to new cgroup */
set_hugetlb_cgroup(newhpage, h_cg);
set_hugetlb_cgroup_rsvd(newhpage, h_cg_rsvd);
list_move(&newhpage->lru, &h->hugepage_activelist);
spin_unlock(&hugetlb_lock);
return;
}
static struct cftype hugetlb_files[] = {
{} /* terminate */
};
struct cgroup_subsys hugetlb_cgrp_subsys = {
.css_alloc = hugetlb_cgroup_css_alloc,
.css_offline = hugetlb_cgroup_css_offline,
.css_free = hugetlb_cgroup_css_free,
.dfl_cftypes = hugetlb_files,
.legacy_cftypes = hugetlb_files,
};