mm, hugetlb_cgroup: round limit_in_bytes down to hugepage size
The page_counter rounds limits down to page size values. This makes
sense, except in the case of hugetlb_cgroup where it's not possible to
charge partial hugepages. If the hugetlb_cgroup margin is less than the
hugepage size being charged, it will fail as expected.
Round the hugetlb_cgroup limit down to hugepage size, since it is the
effective limit of the cgroup.
For consistency, round down PAGE_COUNTER_MAX as well when a
hugetlb_cgroup is created: this prevents error reports when a user
cannot restore the value to the kernel default.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nikolay Borisov <kernel@kyup.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index d8fb10d..eec1150 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -67,26 +67,42 @@
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 *counter = &h_cgroup->hugepage[idx];
+ struct page_counter *parent = NULL;
+ unsigned long limit;
+ int ret;
+
+ if (parent_h_cgroup)
+ parent = &parent_h_cgroup->hugepage[idx];
+ page_counter_init(counter, parent);
+
+ limit = round_down(PAGE_COUNTER_MAX,
+ 1 << huge_page_order(&hstates[idx]));
+ ret = page_counter_limit(counter, 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;
- int idx;
h_cgroup = kzalloc(sizeof(*h_cgroup), GFP_KERNEL);
if (!h_cgroup)
return ERR_PTR(-ENOMEM);
- if (parent_h_cgroup) {
- for (idx = 0; idx < HUGE_MAX_HSTATE; idx++)
- page_counter_init(&h_cgroup->hugepage[idx],
- &parent_h_cgroup->hugepage[idx]);
- } else {
+ if (!parent_h_cgroup)
root_h_cgroup = h_cgroup;
- for (idx = 0; idx < HUGE_MAX_HSTATE; idx++)
- page_counter_init(&h_cgroup->hugepage[idx], NULL);
- }
+
+ hugetlb_cgroup_init(h_cgroup, parent_h_cgroup);
return &h_cgroup->css;
}
@@ -285,6 +301,7 @@
return ret;
idx = MEMFILE_IDX(of_cft(of)->private);
+ nr_pages = round_down(nr_pages, 1 << huge_page_order(&hstates[idx]));
switch (MEMFILE_ATTR(of_cft(of)->private)) {
case RES_LIMIT: