hugetlb/cgroup: add hugetlb cgroup control files

Add the control files for hugetlb controller

[akpm@linux-foundation.org: s/CONFIG_CGROUP_HUGETLB_RES_CTLR/CONFIG_MEMCG_HUGETLB/g]
[akpm@linux-foundation.org: s/CONFIG_MEMCG_HUGETLB/CONFIG_CGROUP_HUGETLB/]
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 129 insertions, 0 deletions

diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index bc518bedea98..d1ca1196e62f 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -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;
 
@@ -257,6 +261,131 @@ 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;
+}
+
 struct cgroup_subsys hugetlb_subsys = {
         .name = "hugetlb",
         .create     = hugetlb_cgroup_create,