/* * * Copyright IBM Corporation, 2012 * Author Aneesh Kumar K.V * * Cgroup v2 * Copyright (C) 2019 Red Hat, Inc. * Author: Giuseppe Scrivano * * 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 #include #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val)) #define MEMFILE_IDX(val) (((val) >> 16) & 0xffff) #define MEMFILE_ATTR(val) ((val) & 0xffff) #define hugetlb_cgroup_from_counter(counter, idx) \ container_of(counter, struct hugetlb_cgroup, hugepage[idx]) static struct hugetlb_cgroup *root_h_cgroup __read_mostly; static inline struct page_counter * __hugetlb_cgroup_counter_from_cgroup(struct hugetlb_cgroup *h_cg, int idx, bool rsvd) { if (rsvd) return &h_cg->rsvd_hugepage[idx]; return &h_cg->hugepage[idx]; } static inline struct page_counter * hugetlb_cgroup_counter_from_cgroup(struct hugetlb_cgroup *h_cg, int idx) { return __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, false); } static inline struct page_counter * hugetlb_cgroup_counter_from_cgroup_rsvd(struct hugetlb_cgroup *h_cg, int idx) { return __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, true); } static inline struct hugetlb_cgroup *hugetlb_cgroup_from_css(struct cgroup_subsys_state *s) { return s ? container_of(s, struct hugetlb_cgroup, css) : NULL; } static inline struct hugetlb_cgroup *hugetlb_cgroup_from_task(struct task_struct *task) { return hugetlb_cgroup_from_css(task_css(task, hugetlb_cgrp_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 hugetlb_cgroup *h_cg) { return hugetlb_cgroup_from_css(h_cg->css.parent); } static inline bool hugetlb_cgroup_have_usage(struct hugetlb_cgroup *h_cg) { int idx; for (idx = 0; idx < hugetlb_max_hstate; idx++) { if (page_counter_read( hugetlb_cgroup_counter_from_cgroup(h_cg, idx)) || page_counter_read(hugetlb_cgroup_counter_from_cgroup_rsvd( h_cg, idx))) { return true; } } 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 *fault_parent = NULL; struct page_counter *rsvd_parent = NULL; unsigned long limit; int ret; if (parent_h_cgroup) { fault_parent = hugetlb_cgroup_counter_from_cgroup( parent_h_cgroup, idx); rsvd_parent = hugetlb_cgroup_counter_from_cgroup_rsvd( parent_h_cgroup, idx); } page_counter_init(hugetlb_cgroup_counter_from_cgroup(h_cgroup, idx), fault_parent); page_counter_init( hugetlb_cgroup_counter_from_cgroup_rsvd(h_cgroup, idx), rsvd_parent); limit = round_down(PAGE_COUNTER_MAX, 1 << huge_page_order(&hstates[idx])); ret = page_counter_set_max( hugetlb_cgroup_counter_from_cgroup(h_cgroup, idx), limit); VM_BUG_ON(ret); ret = page_counter_set_max( hugetlb_cgroup_counter_from_cgroup_rsvd(h_cgroup, idx), 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; h_cgroup = kzalloc(sizeof(*h_cgroup), GFP_KERNEL); if (!h_cgroup) return ERR_PTR(-ENOMEM); if (!parent_h_cgroup) root_h_cgroup = h_cgroup; hugetlb_cgroup_init(h_cgroup, parent_h_cgroup); return &h_cgroup->css; } static void hugetlb_cgroup_css_free(struct cgroup_subsys_state *css) { struct hugetlb_cgroup *h_cgroup; h_cgroup = hugetlb_cgroup_from_css(css); 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 hugetlb_cgroup *h_cg, struct page *page) { unsigned int nr_pages; struct page_counter *counter; struct hugetlb_cgroup *page_hcg; struct hugetlb_cgroup *parent = parent_hugetlb_cgroup(h_cg); 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; nr_pages = compound_nr(page); if (!parent) { parent = root_h_cgroup; /* root has no limit */ page_counter_charge(&parent->hugepage[idx], nr_pages); } counter = &h_cg->hugepage[idx]; /* Take the pages off the local counter */ page_counter_cancel(counter, nr_pages); set_hugetlb_cgroup(page, parent); out: return; } /* * Force the hugetlb cgroup to empty the hugetlb resources by moving them to * the parent cgroup. */ static void hugetlb_cgroup_css_offline(struct cgroup_subsys_state *css) { struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css); struct hstate *h; struct page *page; int idx = 0; do { for_each_hstate(h) { spin_lock(&hugetlb_lock); list_for_each_entry(page, &h->hugepage_activelist, lru) hugetlb_cgroup_move_parent(idx, h_cg, page); spin_unlock(&hugetlb_lock); idx++; } cond_resched(); } while (hugetlb_cgroup_have_usage(h_cg)); } static inline void hugetlb_event(struct hugetlb_cgroup *hugetlb, int idx, enum hugetlb_memory_event event) { atomic_long_inc(&hugetlb->events_local[idx][event]); cgroup_file_notify(&hugetlb->events_local_file[idx]); do { atomic_long_inc(&hugetlb->events[idx][event]); cgroup_file_notify(&hugetlb->events_file[idx]); } while ((hugetlb = parent_hugetlb_cgroup(hugetlb)) && !hugetlb_cgroup_is_root(hugetlb)); } static int __hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages, struct hugetlb_cgroup **ptr, bool rsvd) { int ret = 0; struct page_counter *counter; struct hugetlb_cgroup *h_cg = NULL; 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(); if (!page_counter_try_charge( __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd), nr_pages, &counter)) { ret = -ENOMEM; hugetlb_event(h_cg, idx, HUGETLB_MAX); css_put(&h_cg->css); goto done; } /* Reservations take a reference to the css because they do not get * reparented. */ if (!rsvd) css_put(&h_cg->css); done: *ptr = h_cg; return ret; } int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages, struct hugetlb_cgroup **ptr) { return __hugetlb_cgroup_charge_cgroup(idx, nr_pages, ptr, false); } int hugetlb_cgroup_charge_cgroup_rsvd(int idx, unsigned long nr_pages, struct hugetlb_cgroup **ptr) { return __hugetlb_cgroup_charge_cgroup(idx, nr_pages, ptr, true); } /* Should be called with hugetlb_lock held */ static void __hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages, struct hugetlb_cgroup *h_cg, struct page *page, bool rsvd) { if (hugetlb_cgroup_disabled() || !h_cg) return; __set_hugetlb_cgroup(page, h_cg, rsvd); return; } void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages, struct hugetlb_cgroup *h_cg, struct page *page) { __hugetlb_cgroup_commit_charge(idx, nr_pages, h_cg, page, false); } void hugetlb_cgroup_commit_charge_rsvd(int idx, unsigned long nr_pages, struct hugetlb_cgroup *h_cg, struct page *page) { __hugetlb_cgroup_commit_charge(idx, nr_pages, h_cg, page, true); } /* * Should be called with hugetlb_lock held */ static void __hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages, struct page *page, bool rsvd) { struct hugetlb_cgroup *h_cg; if (hugetlb_cgroup_disabled()) return; lockdep_assert_held(&hugetlb_lock); h_cg = __hugetlb_cgroup_from_page(page, rsvd); if (unlikely(!h_cg)) return; __set_hugetlb_cgroup(page, NULL, rsvd); page_counter_uncharge(__hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd), nr_pages); if (rsvd) css_put(&h_cg->css); return; } void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages, struct page *page) { __hugetlb_cgroup_uncharge_page(idx, nr_pages, page, false); } void hugetlb_cgroup_uncharge_page_rsvd(int idx, unsigned long nr_pages, struct page *page) { __hugetlb_cgroup_uncharge_page(idx, nr_pages, page, true); } static void __hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages, struct hugetlb_cgroup *h_cg, bool rsvd) { if (hugetlb_cgroup_disabled() || !h_cg) return; if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER) return; page_counter_uncharge(__hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd), nr_pages); if (rsvd) css_put(&h_cg->css); } void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages, struct hugetlb_cgroup *h_cg) { __hugetlb_cgroup_uncharge_cgroup(idx, nr_pages, h_cg, false); } void hugetlb_cgroup_uncharge_cgroup_rsvd(int idx, unsigned long nr_pages, struct hugetlb_cgroup *h_cg) { __hugetlb_cgroup_uncharge_cgroup(idx, nr_pages, h_cg, true); } void hugetlb_cgroup_uncharge_counter(struct resv_map *resv, unsigned long start, unsigned long end) { if (hugetlb_cgroup_disabled() || !resv || !resv->reservation_counter || !resv->css) return; page_counter_uncharge(resv->reservation_counter, (end - start) * resv->pages_per_hpage); css_put(resv->css); } void hugetlb_cgroup_uncharge_file_region(struct resv_map *resv, struct file_region *rg, unsigned long nr_pages) { if (hugetlb_cgroup_disabled() || !resv || !rg || !nr_pages) return; if (rg->reservation_counter && resv->pages_per_hpage && nr_pages > 0 && !resv->reservation_counter) { page_counter_uncharge(rg->reservation_counter, nr_pages * resv->pages_per_hpage); css_put(rg->css); } } enum { RES_USAGE, RES_RSVD_USAGE, RES_LIMIT, RES_RSVD_LIMIT, RES_MAX_USAGE, RES_RSVD_MAX_USAGE, RES_FAILCNT, RES_RSVD_FAILCNT, }; static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css, struct cftype *cft) { struct page_counter *counter; struct page_counter *rsvd_counter; struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css); counter = &h_cg->hugepage[MEMFILE_IDX(cft->private)]; rsvd_counter = &h_cg->rsvd_hugepage[MEMFILE_IDX(cft->private)]; switch (MEMFILE_ATTR(cft->private)) { case RES_USAGE: return (u64)page_counter_read(counter) * PAGE_SIZE; case RES_RSVD_USAGE: return (u64)page_counter_read(rsvd_counter) * PAGE_SIZE; case RES_LIMIT: return (u64)counter->max * PAGE_SIZE; case RES_RSVD_LIMIT: return (u64)rsvd_counter->max * PAGE_SIZE; case RES_MAX_USAGE: return (u64)counter->watermark * PAGE_SIZE; case RES_RSVD_MAX_USAGE: return (u64)rsvd_counter->watermark * PAGE_SIZE; case RES_FAILCNT: return counter->failcnt; case RES_RSVD_FAILCNT: return rsvd_counter->failcnt; default: BUG(); } } static int hugetlb_cgroup_read_u64_max(struct seq_file *seq, void *v) { int idx; u64 val; struct cftype *cft = seq_cft(seq); unsigned long limit; struct page_counter *counter; struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(seq_css(seq)); idx = MEMFILE_IDX(cft->private); counter = &h_cg->hugepage[idx]; limit = round_down(PAGE_COUNTER_MAX, 1 << huge_page_order(&hstates[idx])); switch (MEMFILE_ATTR(cft->private)) { case RES_RSVD_USAGE: counter = &h_cg->rsvd_hugepage[idx]; fallthrough; case RES_USAGE: val = (u64)page_counter_read(counter); seq_printf(seq, "%llu\n", val * PAGE_SIZE); break; case RES_RSVD_LIMIT: counter = &h_cg->rsvd_hugepage[idx]; fallthrough; case RES_LIMIT: val = (u64)counter->max; if (val == limit) seq_puts(seq, "max\n"); else seq_printf(seq, "%llu\n", val * PAGE_SIZE); break; default: BUG(); } return 0; } static DEFINE_MUTEX(hugetlb_limit_mutex); static ssize_t hugetlb_cgroup_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off, const char *max) { int ret, idx; unsigned long nr_pages; struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of)); bool rsvd = false; if (hugetlb_cgroup_is_root(h_cg)) /* Can't set limit on root */ return -EINVAL; buf = strstrip(buf); ret = page_counter_memparse(buf, max, &nr_pages); if (ret) 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_RSVD_LIMIT: rsvd = true; fallthrough; case RES_LIMIT: mutex_lock(&hugetlb_limit_mutex); ret = page_counter_set_max( __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd), nr_pages); mutex_unlock(&hugetlb_limit_mutex); break; default: ret = -EINVAL; break; } return ret ?: nbytes; } static ssize_t hugetlb_cgroup_write_legacy(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { return hugetlb_cgroup_write(of, buf, nbytes, off, "-1"); } static ssize_t hugetlb_cgroup_write_dfl(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { return hugetlb_cgroup_write(of, buf, nbytes, off, "max"); } 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, *rsvd_counter; struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of)); counter = &h_cg->hugepage[MEMFILE_IDX(of_cft(of)->private)]; rsvd_counter = &h_cg->rsvd_hugepage[MEMFILE_IDX(of_cft(of)->private)]; switch (MEMFILE_ATTR(of_cft(of)->private)) { case RES_MAX_USAGE: page_counter_reset_watermark(counter); break; case RES_RSVD_MAX_USAGE: page_counter_reset_watermark(rsvd_counter); break; case RES_FAILCNT: counter->failcnt = 0; break; case RES_RSVD_FAILCNT: rsvd_counter->failcnt = 0; break; default: ret = -EINVAL; break; } return ret ?: nbytes; } static char *mem_fmt(char *buf, int size, unsigned long hsize) { if (hsize >= (1UL << 30)) snprintf(buf, size, "%luGB", hsize >> 30); else if (hsize >= (1UL << 20)) snprintf(buf, size, "%luMB", hsize >> 20); else snprintf(buf, size, "%luKB", hsize >> 10); return buf; } static int __hugetlb_events_show(struct seq_file *seq, bool local) { int idx; long max; struct cftype *cft = seq_cft(seq); struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(seq_css(seq)); idx = MEMFILE_IDX(cft->private); if (local) max = atomic_long_read(&h_cg->events_local[idx][HUGETLB_MAX]); else max = atomic_long_read(&h_cg->events[idx][HUGETLB_MAX]); seq_printf(seq, "max %lu\n", max); return 0; } static int hugetlb_events_show(struct seq_file *seq, void *v) { return __hugetlb_events_show(seq, false); } static int hugetlb_events_local_show(struct seq_file *seq, void *v) { return __hugetlb_events_show(seq, true); } static void __init __hugetlb_cgroup_file_dfl_init(int idx) { char buf[32]; struct cftype *cft; struct hstate *h = &hstates[idx]; /* format the size */ mem_fmt(buf, sizeof(buf), huge_page_size(h)); /* Add the limit file */ cft = &h->cgroup_files_dfl[0]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.max", buf); cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT); cft->seq_show = hugetlb_cgroup_read_u64_max; cft->write = hugetlb_cgroup_write_dfl; cft->flags = CFTYPE_NOT_ON_ROOT; /* Add the reservation limit file */ cft = &h->cgroup_files_dfl[1]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.max", buf); cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_LIMIT); cft->seq_show = hugetlb_cgroup_read_u64_max; cft->write = hugetlb_cgroup_write_dfl; cft->flags = CFTYPE_NOT_ON_ROOT; /* Add the current usage file */ cft = &h->cgroup_files_dfl[2]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.current", buf); cft->private = MEMFILE_PRIVATE(idx, RES_USAGE); cft->seq_show = hugetlb_cgroup_read_u64_max; cft->flags = CFTYPE_NOT_ON_ROOT; /* Add the current reservation usage file */ cft = &h->cgroup_files_dfl[3]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.current", buf); cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_USAGE); cft->seq_show = hugetlb_cgroup_read_u64_max; cft->flags = CFTYPE_NOT_ON_ROOT; /* Add the events file */ cft = &h->cgroup_files_dfl[4]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.events", buf); cft->private = MEMFILE_PRIVATE(idx, 0); cft->seq_show = hugetlb_events_show; cft->file_offset = offsetof(struct hugetlb_cgroup, events_file[idx]), cft->flags = CFTYPE_NOT_ON_ROOT; /* Add the events.local file */ cft = &h->cgroup_files_dfl[5]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.events.local", buf); cft->private = MEMFILE_PRIVATE(idx, 0); cft->seq_show = hugetlb_events_local_show; cft->file_offset = offsetof(struct hugetlb_cgroup, events_local_file[idx]), cft->flags = CFTYPE_NOT_ON_ROOT; /* NULL terminate the last cft */ cft = &h->cgroup_files_dfl[6]; memset(cft, 0, sizeof(*cft)); WARN_ON(cgroup_add_dfl_cftypes(&hugetlb_cgrp_subsys, h->cgroup_files_dfl)); } static void __init __hugetlb_cgroup_file_legacy_init(int idx) { char buf[32]; struct cftype *cft; struct hstate *h = &hstates[idx]; /* format the size */ mem_fmt(buf, sizeof(buf), huge_page_size(h)); /* Add the limit file */ cft = &h->cgroup_files_legacy[0]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.limit_in_bytes", buf); cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT); cft->read_u64 = hugetlb_cgroup_read_u64; cft->write = hugetlb_cgroup_write_legacy; /* Add the reservation limit file */ cft = &h->cgroup_files_legacy[1]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.limit_in_bytes", buf); cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_LIMIT); cft->read_u64 = hugetlb_cgroup_read_u64; cft->write = hugetlb_cgroup_write_legacy; /* Add the usage file */ cft = &h->cgroup_files_legacy[2]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.usage_in_bytes", buf); cft->private = MEMFILE_PRIVATE(idx, RES_USAGE); cft->read_u64 = hugetlb_cgroup_read_u64; /* Add the reservation usage file */ cft = &h->cgroup_files_legacy[3]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.usage_in_bytes", buf); cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_USAGE); cft->read_u64 = hugetlb_cgroup_read_u64; /* Add the MAX usage file */ cft = &h->cgroup_files_legacy[4]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.max_usage_in_bytes", buf); cft->private = MEMFILE_PRIVATE(idx, 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_legacy[5]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.max_usage_in_bytes", buf); cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_MAX_USAGE); cft->write = hugetlb_cgroup_reset; cft->read_u64 = hugetlb_cgroup_read_u64; /* Add the failcntfile */ cft = &h->cgroup_files_legacy[6]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.failcnt", buf); cft->private = MEMFILE_PRIVATE(idx, RES_FAILCNT); cft->write = hugetlb_cgroup_reset; cft->read_u64 = hugetlb_cgroup_read_u64; /* Add the reservation failcntfile */ cft = &h->cgroup_files_legacy[7]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.failcnt", buf); cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_FAILCNT); cft->write = hugetlb_cgroup_reset; cft->read_u64 = hugetlb_cgroup_read_u64; /* NULL terminate the last cft */ cft = &h->cgroup_files_legacy[8]; memset(cft, 0, sizeof(*cft)); WARN_ON(cgroup_add_legacy_cftypes(&hugetlb_cgrp_subsys, h->cgroup_files_legacy)); } static void __init __hugetlb_cgroup_file_init(int idx) { __hugetlb_cgroup_file_dfl_init(idx); __hugetlb_cgroup_file_legacy_init(idx); } void __init hugetlb_cgroup_file_init(void) { struct hstate *h; for_each_hstate(h) { /* * Add cgroup control files only if the huge page consists * of more than two normal pages. This is because we use * page[2].private for storing cgroup details. */ if (huge_page_order(h) >= HUGETLB_CGROUP_MIN_ORDER) __hugetlb_cgroup_file_init(hstate_index(h)); } } /* * hugetlb_lock will make sure a parallel cgroup rmdir won't happen * when we migrate hugepages */ void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage) { struct hugetlb_cgroup *h_cg; struct hugetlb_cgroup *h_cg_rsvd; struct hstate *h = page_hstate(oldhpage); if (hugetlb_cgroup_disabled()) return; VM_BUG_ON_PAGE(!PageHuge(oldhpage), oldhpage); spin_lock(&hugetlb_lock); h_cg = hugetlb_cgroup_from_page(oldhpage); h_cg_rsvd = hugetlb_cgroup_from_page_rsvd(oldhpage); set_hugetlb_cgroup(oldhpage, NULL); set_hugetlb_cgroup_rsvd(oldhpage, NULL); /* move the h_cg details to new cgroup */ set_hugetlb_cgroup(newhpage, h_cg); set_hugetlb_cgroup_rsvd(newhpage, h_cg_rsvd); list_move(&newhpage->lru, &h->hugepage_activelist); spin_unlock(&hugetlb_lock); return; } static struct cftype hugetlb_files[] = { {} /* terminate */ }; struct cgroup_subsys hugetlb_cgrp_subsys = { .css_alloc = hugetlb_cgroup_css_alloc, .css_offline = hugetlb_cgroup_css_offline, .css_free = hugetlb_cgroup_css_free, .dfl_cftypes = hugetlb_files, .legacy_cftypes = hugetlb_files, };