hugetlb: do not fail in hugetlb_cgroup_pre_destroy
[platform/adaptation/renesas_rcar/renesas_kernel.git] / mm / hugetlb_cgroup.c
index bc518be..dc595c6 100644 (file)
@@ -26,6 +26,10 @@ struct hugetlb_cgroup {
        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;
 
@@ -155,14 +159,9 @@ static int hugetlb_cgroup_pre_destroy(struct cgroup *cgroup)
 {
        struct hstate *h;
        struct page *page;
-       int ret = 0, idx = 0;
+       int 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)
@@ -173,8 +172,8 @@ static int hugetlb_cgroup_pre_destroy(struct cgroup *cgroup)
                }
                cond_resched();
        } while (hugetlb_cgroup_have_usage(cgroup));
-out:
-       return ret;
+
+       return 0;
 }
 
 int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
@@ -209,6 +208,7 @@ done:
        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)
@@ -216,9 +216,7 @@ void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
        if (hugetlb_cgroup_disabled() || !h_cg)
                return;
 
-       spin_lock(&hugetlb_lock);
        set_hugetlb_cgroup(page, h_cg);
-       spin_unlock(&hugetlb_lock);
        return;
 }
 
@@ -257,6 +255,155 @@ void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
        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,