From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
This add support for memcg removal with HugeTLB resource usage.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
---
include/linux/hugetlb.h | 6 ++++
include/linux/memcontrol.h | 15 +++++++++-
mm/hugetlb.c | 41 ++++++++++++++++++++++++++
mm/memcontrol.c | 68 +++++++++++++++++++++++++++++++++++++------
4 files changed, 119 insertions(+), 11 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 6919100..32e948c 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -349,11 +349,17 @@ static inline unsigned int pages_per_huge_page(struct hstate *h)
#ifdef CONFIG_MEM_RES_CTLR_HUGETLB
extern int register_hugetlb_memcg_files(struct cgroup *cgroup,
struct cgroup_subsys *ss);
+extern int hugetlb_force_memcg_empty(struct cgroup *cgroup);
#else
static inline int register_hugetlb_memcg_files(struct cgroup *cgroup,
struct cgroup_subsys *ss)
{
return 0;
}
+
+static inline int hugetlb_force_memcg_empty(struct cgroup *cgroup)
+{
+ return 0;
+}
#endif
#endif /* _LINUX_HUGETLB_H */
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 73900b9..0980122 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -441,7 +441,9 @@ extern void mem_cgroup_hugetlb_uncharge_page(int idx, unsigned long nr_pages,
extern void mem_cgroup_hugetlb_uncharge_memcg(int idx, unsigned long nr_pages,
struct mem_cgroup *memcg);
extern int mem_cgroup_hugetlb_file_init(int idx);
-
+extern int mem_cgroup_move_hugetlb_parent(int idx, struct cgroup *cgroup,
+ struct page *page);
+extern bool mem_cgroup_have_hugetlb_usage(struct cgroup *cgroup);
#else
static inline int
mem_cgroup_hugetlb_charge_page(int idx, unsigned long nr_pages,
@@ -477,6 +479,17 @@ static inline int mem_cgroup_hugetlb_file_init(int idx)
return 0;
}
+static inline int
+mem_cgroup_move_hugetlb_parent(int idx, struct cgroup *cgroup,
+ struct page *page)
+{
+ return 0;
+}
+
+static inline bool mem_cgroup_have_hugetlb_usage(struct cgroup *cgroup)
+{
+ return 0;
+}
#endif /* CONFIG_MEM_RES_CTLR_HUGETLB */
#endif /* _LINUX_MEMCONTROL_H */
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 8fd465d..685f0d5 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1842,6 +1842,47 @@ int register_hugetlb_memcg_files(struct cgroup *cgroup,
}
return ret;
}
+
+/*
+ * Force the memcg to empty the hugetlb resources by moving them to
+ * the parent cgroup. We can fail if the parent cgroup's limit prevented
+ * the charging. This should only happen if use_hierarchy is not set.
+ */
+int hugetlb_force_memcg_empty(struct cgroup *cgroup)
+{
+ struct hstate *h;
+ struct page *page;
+ int ret = 0, idx = 0;
+
+ do {
+ if (cgroup_task_count(cgroup) || !list_empty(&cgroup->children))
+ goto out;
+ /*
+ * If the task doing the cgroup_rmdir got a signal
+ * we don't really need to loop till the hugetlb resource
+ * usage become zero.
+ */
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ goto out;
+ }
+ for_each_hstate(h) {
+ spin_lock(&hugetlb_lock);
+ list_for_each_entry(page, &h->hugepage_activelist, lru) {
+ ret = mem_cgroup_move_hugetlb_parent(idx, cgroup, page);
+ if (ret) {
+ spin_unlock(&hugetlb_lock);
+ goto out;
+ }
+ }
+ spin_unlock(&hugetlb_lock);
+ idx++;
+ }
+ cond_resched();
+ } while (mem_cgroup_have_hugetlb_usage(cgroup));
+out:
+ return ret;
+}
#endif
/* Should be called on processing a hugepagesz=... option */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 4900b72..e29d86d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3171,9 +3171,11 @@ static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
#endif
#ifdef CONFIG_MEM_RES_CTLR_HUGETLB
-static bool mem_cgroup_have_hugetlb_usage(struct mem_cgroup *memcg)
+bool mem_cgroup_have_hugetlb_usage(struct cgroup *cgroup)
{
int idx;
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgroup);
+
for (idx = 0; idx < hugetlb_max_hstate; idx++) {
if (memcg->hugepage[idx].usage > 0)
return 1;
@@ -3285,10 +3287,57 @@ void mem_cgroup_hugetlb_uncharge_memcg(int idx, unsigned long nr_pages,
res_counter_uncharge(&memcg->hugepage[idx], csize);
return;
}
-#else
-static bool mem_cgroup_have_hugetlb_usage(struct mem_cgroup *memcg)
+
+int mem_cgroup_move_hugetlb_parent(int idx, struct cgroup *cgroup,
+ struct page *page)
{
- return 0;
+ struct page_cgroup *pc;
+ int csize, ret = 0;
+ struct res_counter *fail_res;
+ struct cgroup *pcgrp = cgroup->parent;
+ struct mem_cgroup *parent = mem_cgroup_from_cont(pcgrp);
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgroup);
+
+ if (!get_page_unless_zero(page))
+ goto out;
+
+ pc = lookup_page_cgroup(page);
+ lock_page_cgroup(pc);
+ if (!PageCgroupUsed(pc) || pc->mem_cgroup != memcg)
+ goto err_out;
+
+ csize = PAGE_SIZE << compound_order(page);
+ /*
+ * uncharge from child and charge the parent. If we have
+ * use_hierarchy set, we can never fail here. In-order to make
+ * sure we don't get -ENOMEM on parent charge, we first uncharge
+ * the child and then charge the parent.
+ */
+ if (parent->use_hierarchy) {
+ res_counter_uncharge(&memcg->hugepage[idx], csize);
+ if (!mem_cgroup_is_root(parent))
+ ret = res_counter_charge(&parent->hugepage[idx],
+ csize, &fail_res);
+ } else {
+ if (!mem_cgroup_is_root(parent)) {
+ ret = res_counter_charge(&parent->hugepage[idx],
+ csize, &fail_res);
+ if (ret) {
+ ret = -EBUSY;
+ goto err_out;
+ }
+ }
+ res_counter_uncharge(&memcg->hugepage[idx], csize);
+ }
+ /*
+ * caller should have done css_get
+ */
+ pc->mem_cgroup = parent;
+err_out:
+ unlock_page_cgroup(pc);
+ put_page(page);
+out:
+ return ret;
}
#endif /* CONFIG_MEM_RES_CTLR_HUGETLB */
@@ -3806,6 +3855,11 @@ static int mem_cgroup_force_empty(struct mem_cgroup *memcg, bool free_all)
/* should free all ? */
if (free_all)
goto try_to_free;
+
+ /* move the hugetlb charges */
+ ret = hugetlb_force_memcg_empty(cgrp);
+ if (ret)
+ goto out;
move_account:
do {
ret = -EBUSY;
@@ -5103,12 +5157,6 @@ static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
struct cgroup *cont)
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
- /*
- * Don't allow memcg removal if we have HugeTLB resource
- * usage.
- */
- if (mem_cgroup_have_hugetlb_usage(memcg))
- return -EBUSY;
return mem_cgroup_force_empty(memcg, false);
}
--
1.7.9
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