[PATCH v4 1/9] hugetlb_cgroup: Add hugetlb_cgroup reservation counter

From: Mina Almasry
Date: Tue Sep 10 2019 - 19:32:01 EST


These counters will track hugetlb reservations rather than hugetlb
memory faulted in. This patch only adds the counter, following patches
add the charging and uncharging of the counter.

Signed-off-by: Mina Almasry <almasrymina@xxxxxxxxxx>
Acked-by: Hillf Danton <hdanton@xxxxxxxx>
---
include/linux/hugetlb.h | 16 +++++-
mm/hugetlb_cgroup.c | 111 ++++++++++++++++++++++++++++++----------
2 files changed, 100 insertions(+), 27 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index edfca42783192..128ff1aff1c93 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -320,6 +320,20 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,

#ifdef CONFIG_HUGETLB_PAGE

+enum {
+ HUGETLB_RES_USAGE,
+ HUGETLB_RES_RESERVATION_USAGE,
+ HUGETLB_RES_LIMIT,
+ HUGETLB_RES_RESERVATION_LIMIT,
+ HUGETLB_RES_MAX_USAGE,
+ HUGETLB_RES_RESERVATION_MAX_USAGE,
+ HUGETLB_RES_FAILCNT,
+ HUGETLB_RES_RESERVATION_FAILCNT,
+ HUGETLB_RES_NULL,
+ HUGETLB_RES_MAX,
+};
+
+
#define HSTATE_NAME_LEN 32
/* Defines one hugetlb page size */
struct hstate {
@@ -340,7 +354,7 @@ struct hstate {
unsigned int surplus_huge_pages_node[MAX_NUMNODES];
#ifdef CONFIG_CGROUP_HUGETLB
/* cgroup control files */
- struct cftype cgroup_files[5];
+ struct cftype cgroup_files[HUGETLB_RES_MAX];
#endif
char name[HSTATE_NAME_LEN];
};
diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index 68c2f2f3c05b7..51a72624bd1ff 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -25,6 +25,10 @@ struct hugetlb_cgroup {
* the counter to account for hugepages from hugetlb.
*/
struct page_counter hugepage[HUGE_MAX_HSTATE];
+ /*
+ * the counter to account for hugepage reservations from hugetlb.
+ */
+ struct page_counter reserved_hugepage[HUGE_MAX_HSTATE];
};

#define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
@@ -33,6 +37,15 @@ struct hugetlb_cgroup {

static struct hugetlb_cgroup *root_h_cgroup __read_mostly;

+static inline
+struct page_counter *hugetlb_cgroup_get_counter(struct hugetlb_cgroup *h_cg, int idx,
+ bool reserved)
+{
+ if (reserved)
+ return &h_cg->reserved_hugepage[idx];
+ return &h_cg->hugepage[idx];
+}
+
static inline
struct hugetlb_cgroup *hugetlb_cgroup_from_css(struct cgroup_subsys_state *s)
{
@@ -254,30 +267,33 @@ void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
return;
}

-enum {
- RES_USAGE,
- RES_LIMIT,
- RES_MAX_USAGE,
- RES_FAILCNT,
-};
-
static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css,
struct cftype *cft)
{
struct page_counter *counter;
+ struct page_counter *reserved_counter;
struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css);

counter = &h_cg->hugepage[MEMFILE_IDX(cft->private)];
+ reserved_counter = &h_cg->reserved_hugepage[MEMFILE_IDX(cft->private)];

switch (MEMFILE_ATTR(cft->private)) {
- case RES_USAGE:
+ case HUGETLB_RES_USAGE:
return (u64)page_counter_read(counter) * PAGE_SIZE;
- case RES_LIMIT:
+ case HUGETLB_RES_RESERVATION_USAGE:
+ return (u64)page_counter_read(reserved_counter) * PAGE_SIZE;
+ case HUGETLB_RES_LIMIT:
return (u64)counter->max * PAGE_SIZE;
- case RES_MAX_USAGE:
+ case HUGETLB_RES_RESERVATION_LIMIT:
+ return (u64)reserved_counter->max * PAGE_SIZE;
+ case HUGETLB_RES_MAX_USAGE:
return (u64)counter->watermark * PAGE_SIZE;
- case RES_FAILCNT:
+ case HUGETLB_RES_RESERVATION_MAX_USAGE:
+ return (u64)reserved_counter->watermark * PAGE_SIZE;
+ case HUGETLB_RES_FAILCNT:
return counter->failcnt;
+ case HUGETLB_RES_RESERVATION_FAILCNT:
+ return reserved_counter->failcnt;
default:
BUG();
}
@@ -291,6 +307,7 @@ static ssize_t hugetlb_cgroup_write(struct kernfs_open_file *of,
int ret, idx;
unsigned long nr_pages;
struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of));
+ bool reserved = false;

if (hugetlb_cgroup_is_root(h_cg)) /* Can't set limit on root */
return -EINVAL;
@@ -304,9 +321,13 @@ static ssize_t hugetlb_cgroup_write(struct kernfs_open_file *of,
nr_pages = round_down(nr_pages, 1 << huge_page_order(&hstates[idx]));

switch (MEMFILE_ATTR(of_cft(of)->private)) {
- case RES_LIMIT:
+ case HUGETLB_RES_RESERVATION_LIMIT:
+ reserved = true;
+ /* Fall through. */
+ case HUGETLB_RES_LIMIT:
mutex_lock(&hugetlb_limit_mutex);
- ret = page_counter_set_max(&h_cg->hugepage[idx], nr_pages);
+ ret = page_counter_set_max(hugetlb_cgroup_get_counter(h_cg, idx, reserved),
+ nr_pages);
mutex_unlock(&hugetlb_limit_mutex);
break;
default:
@@ -320,18 +341,26 @@ 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;
+ struct page_counter *counter, *reserved_counter;
struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of));

counter = &h_cg->hugepage[MEMFILE_IDX(of_cft(of)->private)];
+ reserved_counter = &h_cg->reserved_hugepage[
+ MEMFILE_IDX(of_cft(of)->private)];

switch (MEMFILE_ATTR(of_cft(of)->private)) {
- case RES_MAX_USAGE:
+ case HUGETLB_RES_MAX_USAGE:
page_counter_reset_watermark(counter);
break;
- case RES_FAILCNT:
+ case HUGETLB_RES_RESERVATION_MAX_USAGE:
+ page_counter_reset_watermark(reserved_counter);
+ break;
+ case HUGETLB_RES_FAILCNT:
counter->failcnt = 0;
break;
+ case HUGETLB_RES_RESERVATION_FAILCNT:
+ reserved_counter->failcnt = 0;
+ break;
default:
ret = -EINVAL;
break;
@@ -357,37 +386,67 @@ static void __init __hugetlb_cgroup_file_init(int idx)
struct hstate *h = &hstates[idx];

/* format the size */
- mem_fmt(buf, 32, huge_page_size(h));
+ mem_fmt(buf, sizeof(buf), huge_page_size(h));

/* Add the limit file */
- cft = &h->cgroup_files[0];
+ cft = &h->cgroup_files[HUGETLB_RES_LIMIT];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.limit_in_bytes", buf);
- cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT);
+ cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_LIMIT);
+ cft->read_u64 = hugetlb_cgroup_read_u64;
+ cft->write = hugetlb_cgroup_write;
+
+ /* Add the reservation limit file */
+ cft = &h->cgroup_files[HUGETLB_RES_RESERVATION_LIMIT];
+ snprintf(cft->name, MAX_CFTYPE_NAME, "%s.reservation_limit_in_bytes",
+ buf);
+ cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_RESERVATION_LIMIT);
cft->read_u64 = hugetlb_cgroup_read_u64;
cft->write = hugetlb_cgroup_write;

/* Add the usage file */
- cft = &h->cgroup_files[1];
+ cft = &h->cgroup_files[HUGETLB_RES_USAGE];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.usage_in_bytes", buf);
- cft->private = MEMFILE_PRIVATE(idx, RES_USAGE);
+ cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_USAGE);
+ cft->read_u64 = hugetlb_cgroup_read_u64;
+
+ /* Add the reservation usage file */
+ cft = &h->cgroup_files[HUGETLB_RES_RESERVATION_USAGE];
+ snprintf(cft->name, MAX_CFTYPE_NAME, "%s.reservation_usage_in_bytes",
+ buf);
+ cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_RESERVATION_USAGE);
cft->read_u64 = hugetlb_cgroup_read_u64;

/* Add the MAX usage file */
- cft = &h->cgroup_files[2];
+ cft = &h->cgroup_files[HUGETLB_RES_MAX_USAGE];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.max_usage_in_bytes", buf);
- cft->private = MEMFILE_PRIVATE(idx, RES_MAX_USAGE);
+ cft->private = MEMFILE_PRIVATE(idx, HUGETLB_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[HUGETLB_RES_RESERVATION_MAX_USAGE];
+ snprintf(cft->name, MAX_CFTYPE_NAME,
+ "%s.reservation_max_usage_in_bytes", buf);
+ cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_RESERVATION_MAX_USAGE);
cft->write = hugetlb_cgroup_reset;
cft->read_u64 = hugetlb_cgroup_read_u64;

/* Add the failcntfile */
- cft = &h->cgroup_files[3];
+ cft = &h->cgroup_files[HUGETLB_RES_FAILCNT];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.failcnt", buf);
- cft->private = MEMFILE_PRIVATE(idx, RES_FAILCNT);
+ cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_FAILCNT);
+ cft->write = hugetlb_cgroup_reset;
+ cft->read_u64 = hugetlb_cgroup_read_u64;
+
+ /* Add the reservation failcntfile */
+ cft = &h->cgroup_files[HUGETLB_RES_RESERVATION_FAILCNT];
+ snprintf(cft->name, MAX_CFTYPE_NAME, "%s.reservation_failcnt", buf);
+ cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_RESERVATION_FAILCNT);
cft->write = hugetlb_cgroup_reset;
cft->read_u64 = hugetlb_cgroup_read_u64;

/* NULL terminate the last cft */
- cft = &h->cgroup_files[4];
+ cft = &h->cgroup_files[HUGETLB_RES_NULL];
memset(cft, 0, sizeof(*cft));

WARN_ON(cgroup_add_legacy_cftypes(&hugetlb_cgrp_subsys,
--
2.23.0.162.g0b9fbb3734-goog