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-rw-r--r--mm/hugetlb_cgroup.c418
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,
+};