/* * * Copyright IBM Corporation, 2012 * Author Aneesh Kumar K.V * * 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 #include #include #include 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, };