diff options
Diffstat (limited to 'mm/hugetlb_cgroup.c')
| -rw-r--r-- | mm/hugetlb_cgroup.c | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c new file mode 100644 index 000000000000..a3f358fb8a0c --- /dev/null +++ b/mm/hugetlb_cgroup.c @@ -0,0 +1,418 @@ +/* + * + * 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]; +}; + +#define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val)) +#define MEMFILE_IDX(val) (((val) >> 16) & 0xffff) +#define MEMFILE_ATTR(val) ((val) & 0xffff) + +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; +} + +/* 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; + 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; +} + +static ssize_t hugetlb_cgroup_read(struct cgroup *cgroup, struct cftype *cft, + struct file *file, char __user *buf, + size_t nbytes, loff_t *ppos) +{ + u64 val; + char str[64]; + int idx, name, len; + struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cgroup); + + idx = MEMFILE_IDX(cft->private); + name = MEMFILE_ATTR(cft->private); + + val = res_counter_read_u64(&h_cg->hugepage[idx], name); + len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val); + return simple_read_from_buffer(buf, nbytes, ppos, str, len); +} + +static int hugetlb_cgroup_write(struct cgroup *cgroup, struct cftype *cft, + const char *buffer) +{ + int idx, name, ret; + unsigned long long val; + struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cgroup); + + idx = MEMFILE_IDX(cft->private); + name = MEMFILE_ATTR(cft->private); + + switch (name) { + case RES_LIMIT: + if (hugetlb_cgroup_is_root(h_cg)) { + /* Can't set limit on root */ + ret = -EINVAL; + break; + } + /* This function does all necessary parse...reuse it */ + ret = res_counter_memparse_write_strategy(buffer, &val); + if (ret) + break; + ret = res_counter_set_limit(&h_cg->hugepage[idx], val); + break; + default: + ret = -EINVAL; + break; + } + return ret; +} + +static int hugetlb_cgroup_reset(struct cgroup *cgroup, unsigned int event) +{ + int idx, name, ret = 0; + struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cgroup); + + idx = MEMFILE_IDX(event); + name = MEMFILE_ATTR(event); + + switch (name) { + case RES_MAX_USAGE: + res_counter_reset_max(&h_cg->hugepage[idx]); + break; + case RES_FAILCNT: + res_counter_reset_failcnt(&h_cg->hugepage[idx]); + break; + default: + ret = -EINVAL; + break; + } + return ret; +} + +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; +} + +int __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 = hugetlb_cgroup_read; + cft->write_string = 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 = hugetlb_cgroup_read; + + /* 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->trigger = hugetlb_cgroup_reset; + cft->read = hugetlb_cgroup_read; + + /* 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->trigger = hugetlb_cgroup_reset; + cft->read = hugetlb_cgroup_read; + + /* NULL terminate the last cft */ + cft = &h->cgroup_files[4]; + memset(cft, 0, sizeof(*cft)); + + WARN_ON(cgroup_add_cftypes(&hugetlb_subsys, h->cgroup_files)); + + return 0; +} + +/* + * 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(!PageHuge(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_subsys = { + .name = "hugetlb", + .create = hugetlb_cgroup_create, + .pre_destroy = hugetlb_cgroup_pre_destroy, + .destroy = hugetlb_cgroup_destroy, + .subsys_id = hugetlb_subsys_id, +}; |