From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- mm/hugetlb_cgroup.c | 422 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 422 insertions(+) create mode 100644 mm/hugetlb_cgroup.c (limited to 'mm/hugetlb_cgroup.c') diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c new file mode 100644 index 000000000..6e0057439 --- /dev/null +++ b/mm/hugetlb_cgroup.c @@ -0,0 +1,422 @@ +/* + * + * 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 +#include + +struct hugetlb_cgroup { + struct cgroup_subsys_state css; + /* + * the counter to account for hugepages from hugetlb. + */ + struct page_counter hugepage[HUGE_MAX_HSTATE]; +}; + +#define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val)) +#define MEMFILE_IDX(val) (((val) >> 16) & 0xffff) +#define MEMFILE_ATTR(val) ((val) & 0xffff) + +static struct hugetlb_cgroup *root_h_cgroup __read_mostly; + +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(&h_cg->hugepage[idx])) + return true; + } + return false; +} + +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 { + root_h_cgroup = h_cgroup; + for (idx = 0; idx < HUGE_MAX_HSTATE; idx++) + page_counter_init(&h_cgroup->hugepage[idx], NULL); + } + 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 = 1 << compound_order(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)); +} + +int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages, + struct hugetlb_cgroup **ptr) +{ + 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_online(&h_cg->css)) { + rcu_read_unlock(); + goto again; + } + rcu_read_unlock(); + + ret = page_counter_try_charge(&h_cg->hugepage[idx], nr_pages, &counter); + css_put(&h_cg->css); +done: + *ptr = h_cg; + return ret; +} + +/* Should be called with hugetlb_lock held */ +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; + + set_hugetlb_cgroup(page, h_cg); + 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; + + if (hugetlb_cgroup_disabled()) + return; + lockdep_assert_held(&hugetlb_lock); + h_cg = hugetlb_cgroup_from_page(page); + if (unlikely(!h_cg)) + return; + set_hugetlb_cgroup(page, NULL); + page_counter_uncharge(&h_cg->hugepage[idx], nr_pages); + return; +} + +void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages, + struct hugetlb_cgroup *h_cg) +{ + if (hugetlb_cgroup_disabled() || !h_cg) + return; + + if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER) + return; + + page_counter_uncharge(&h_cg->hugepage[idx], nr_pages); + return; +} + +enum { + RES_USAGE, + RES_LIMIT, + RES_MAX_USAGE, + RES_FAILCNT, +}; + +static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css, + struct cftype *cft) +{ + struct page_counter *counter; + struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css); + + counter = &h_cg->hugepage[MEMFILE_IDX(cft->private)]; + + switch (MEMFILE_ATTR(cft->private)) { + case RES_USAGE: + return (u64)page_counter_read(counter) * PAGE_SIZE; + case RES_LIMIT: + return (u64)counter->limit * PAGE_SIZE; + case RES_MAX_USAGE: + return (u64)counter->watermark * PAGE_SIZE; + case RES_FAILCNT: + return counter->failcnt; + default: + BUG(); + } +} + +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) +{ + int ret, idx; + unsigned long nr_pages; + struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of)); + + if (hugetlb_cgroup_is_root(h_cg)) /* Can't set limit on root */ + return -EINVAL; + + buf = strstrip(buf); + ret = page_counter_memparse(buf, "-1", &nr_pages); + if (ret) + return ret; + + idx = MEMFILE_IDX(of_cft(of)->private); + + switch (MEMFILE_ATTR(of_cft(of)->private)) { + case RES_LIMIT: + mutex_lock(&hugetlb_limit_mutex); + ret = page_counter_limit(&h_cg->hugepage[idx], nr_pages); + mutex_unlock(&hugetlb_limit_mutex); + break; + default: + ret = -EINVAL; + break; + } + return ret ?: nbytes; +} + +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; + struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of)); + + counter = &h_cg->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_FAILCNT: + 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 void __init __hugetlb_cgroup_file_init(int idx) +{ + char buf[32]; + struct cftype *cft; + struct hstate *h = &hstates[idx]; + + /* format the size */ + mem_fmt(buf, 32, huge_page_size(h)); + + /* Add the limit file */ + cft = &h->cgroup_files[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; + + /* Add the usage file */ + cft = &h->cgroup_files[1]; + 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 MAX usage file */ + cft = &h->cgroup_files[2]; + 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 failcntfile */ + cft = &h->cgroup_files[3]; + 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; + + /* NULL terminate the last cft */ + cft = &h->cgroup_files[4]; + memset(cft, 0, sizeof(*cft)); + + WARN_ON(cgroup_add_legacy_cftypes(&hugetlb_cgrp_subsys, + h->cgroup_files)); +} + +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].lru.next 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 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); + set_hugetlb_cgroup(oldhpage, NULL); + + /* move the h_cg details to new cgroup */ + set_hugetlb_cgroup(newhpage, h_cg); + list_move(&newhpage->lru, &h->hugepage_activelist); + spin_unlock(&hugetlb_lock); + return; +} + +struct cgroup_subsys hugetlb_cgrp_subsys = { + .css_alloc = hugetlb_cgroup_css_alloc, + .css_offline = hugetlb_cgroup_css_offline, + .css_free = hugetlb_cgroup_css_free, +}; -- cgit v1.2.3-54-g00ecf