| /* |
| * |
| * Copyright IBM Corporation, 2012 |
| * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.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/slab.h> |
| #include <linux/hugetlb.h> |
| #include <linux/hugetlb_cgroup.h> |
| |
| struct hugetlb_cgroup { |
| struct cgroup_subsys_state css; |
| /* |
| * the counter to account for hugepages from hugetlb. |
| */ |
| struct res_counter hugepage[HUGE_MAX_HSTATE]; |
| }; |
| |
| struct cgroup_subsys hugetlb_subsys __read_mostly; |
| static struct hugetlb_cgroup *root_h_cgroup __read_mostly; |
| |
| static inline |
| struct hugetlb_cgroup *hugetlb_cgroup_from_css(struct cgroup_subsys_state *s) |
| { |
| return container_of(s, struct hugetlb_cgroup, css); |
| } |
| |
| static inline |
| struct hugetlb_cgroup *hugetlb_cgroup_from_cgroup(struct cgroup *cgroup) |
| { |
| return hugetlb_cgroup_from_css(cgroup_subsys_state(cgroup, |
| hugetlb_subsys_id)); |
| } |
| |
| static inline |
| struct hugetlb_cgroup *hugetlb_cgroup_from_task(struct task_struct *task) |
| { |
| return hugetlb_cgroup_from_css(task_subsys_state(task, |
| hugetlb_subsys_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 cgroup *cg) |
| { |
| if (!cg->parent) |
| return NULL; |
| return hugetlb_cgroup_from_cgroup(cg->parent); |
| } |
| |
| static inline bool hugetlb_cgroup_have_usage(struct cgroup *cg) |
| { |
| int idx; |
| struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cg); |
| |
| for (idx = 0; idx < hugetlb_max_hstate; idx++) { |
| if ((res_counter_read_u64(&h_cg->hugepage[idx], RES_USAGE)) > 0) |
| return true; |
| } |
| return false; |
| } |
| |
| static struct cgroup_subsys_state *hugetlb_cgroup_create(struct cgroup *cgroup) |
| { |
| int idx; |
| struct cgroup *parent_cgroup; |
| struct hugetlb_cgroup *h_cgroup, *parent_h_cgroup; |
| |
| h_cgroup = kzalloc(sizeof(*h_cgroup), GFP_KERNEL); |
| if (!h_cgroup) |
| return ERR_PTR(-ENOMEM); |
| |
| parent_cgroup = cgroup->parent; |
| if (parent_cgroup) { |
| parent_h_cgroup = hugetlb_cgroup_from_cgroup(parent_cgroup); |
| for (idx = 0; idx < HUGE_MAX_HSTATE; idx++) |
| res_counter_init(&h_cgroup->hugepage[idx], |
| &parent_h_cgroup->hugepage[idx]); |
| } else { |
| root_h_cgroup = h_cgroup; |
| for (idx = 0; idx < HUGE_MAX_HSTATE; idx++) |
| res_counter_init(&h_cgroup->hugepage[idx], NULL); |
| } |
| return &h_cgroup->css; |
| } |
| |
| static void hugetlb_cgroup_destroy(struct cgroup *cgroup) |
| { |
| struct hugetlb_cgroup *h_cgroup; |
| |
| h_cgroup = hugetlb_cgroup_from_cgroup(cgroup); |
| 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 cgroup *cgroup, |
| struct page *page) |
| { |
| int csize; |
| struct res_counter *counter; |
| struct res_counter *fail_res; |
| struct hugetlb_cgroup *page_hcg; |
| struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cgroup); |
| struct hugetlb_cgroup *parent = parent_hugetlb_cgroup(cgroup); |
| |
| 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; |
| |
| csize = PAGE_SIZE << compound_order(page); |
| if (!parent) { |
| parent = root_h_cgroup; |
| /* root has no limit */ |
| res_counter_charge_nofail(&parent->hugepage[idx], |
| csize, &fail_res); |
| } |
| counter = &h_cg->hugepage[idx]; |
| res_counter_uncharge_until(counter, counter->parent, csize); |
| |
| set_hugetlb_cgroup(page, parent); |
| out: |
| return; |
| } |
| |
| /* |
| * Force the hugetlb cgroup to empty the hugetlb resources by moving them to |
| * the parent cgroup. |
| */ |
| static int hugetlb_cgroup_pre_destroy(struct cgroup *cgroup) |
| { |
| struct hstate *h; |
| struct page *page; |
| int ret = 0, idx = 0; |
| |
| do { |
| if (cgroup_task_count(cgroup) || |
| !list_empty(&cgroup->children)) { |
| ret = -EBUSY; |
| goto out; |
| } |
| for_each_hstate(h) { |
| spin_lock(&hugetlb_lock); |
| list_for_each_entry(page, &h->hugepage_activelist, lru) |
| hugetlb_cgroup_move_parent(idx, cgroup, page); |
| |
| spin_unlock(&hugetlb_lock); |
| idx++; |
| } |
| cond_resched(); |
| } while (hugetlb_cgroup_have_usage(cgroup)); |
| out: |
| return ret; |
| } |
| |
| int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages, |
| struct hugetlb_cgroup **ptr) |
| { |
| int ret = 0; |
| struct res_counter *fail_res; |
| struct hugetlb_cgroup *h_cg = NULL; |
| unsigned long csize = nr_pages * PAGE_SIZE; |
| |
| 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(); |
| |
| ret = res_counter_charge(&h_cg->hugepage[idx], csize, &fail_res); |
| css_put(&h_cg->css); |
| done: |
| *ptr = h_cg; |
| return ret; |
| } |
| |
| void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages, |
| struct hugetlb_cgroup *h_cg, |
| struct page *page) |
| { |
| if (hugetlb_cgroup_disabled() || !h_cg) |
| return; |
| |
| spin_lock(&hugetlb_lock); |
| set_hugetlb_cgroup(page, h_cg); |
| spin_unlock(&hugetlb_lock); |
| return; |
| } |
| |
| /* |
| * Should be called with hugetlb_lock held |
| */ |
| void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages, |
| struct page *page) |
| { |
| struct hugetlb_cgroup *h_cg; |
| unsigned long csize = nr_pages * PAGE_SIZE; |
| |
| if (hugetlb_cgroup_disabled()) |
| return; |
| VM_BUG_ON(!spin_is_locked(&hugetlb_lock)); |
| h_cg = hugetlb_cgroup_from_page(page); |
| if (unlikely(!h_cg)) |
| return; |
| set_hugetlb_cgroup(page, NULL); |
| res_counter_uncharge(&h_cg->hugepage[idx], csize); |
| return; |
| } |
| |
| void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages, |
| struct hugetlb_cgroup *h_cg) |
| { |
| unsigned long csize = nr_pages * PAGE_SIZE; |
| |
| if (hugetlb_cgroup_disabled() || !h_cg) |
| return; |
| |
| if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER) |
| return; |
| |
| res_counter_uncharge(&h_cg->hugepage[idx], csize); |
| return; |
| } |
| |
| struct cgroup_subsys hugetlb_subsys = { |
| .name = "hugetlb", |
| .create = hugetlb_cgroup_create, |
| .pre_destroy = hugetlb_cgroup_pre_destroy, |
| .destroy = hugetlb_cgroup_destroy, |
| .subsys_id = hugetlb_subsys_id, |
| }; |