blk-cgroup: Introduce cgroup changes for throttling policy

o cgroup chagnes for throttle policy.

o Introduces READ and WRITE bytes per second throttling rules.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 29 insertions, 1 deletions

diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index c8de2598429d..1b738827b2f6 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -17,6 +17,7 @@
 
 enum blkio_policy_id {
         BLKIO_POLICY_PROP = 0,          /* Proportional Bandwidth division */
+        BLKIO_POLICY_THROTL,            /* Throttling */
 };
 
 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
@@ -88,6 +89,14 @@ enum blkcg_file_name_prop {
         BLKIO_PROP_dequeue,
 };
 
+/* cgroup files owned by throttle policy */
+enum blkcg_file_name_throtl {
+        BLKIO_THROTL_read_bps_device,
+        BLKIO_THROTL_write_bps_device,
+        BLKIO_THROTL_io_service_bytes,
+        BLKIO_THROTL_io_serviced,
+};
+
 struct blkio_cgroup {
         struct cgroup_subsys_state css;
         unsigned int weight;
@@ -146,23 +155,42 @@ struct blkio_group {
 struct blkio_policy_node {
         struct list_head node;
         dev_t dev;
-        unsigned int weight;
         /* This node belongs to max bw policy or porportional weight policy */
         enum blkio_policy_id plid;
         /* cgroup file to which this rule belongs to */
         int fileid;
+
+        union {
+                unsigned int weight;
+                /*
+                 * Rate read/write in terms of byptes per second
+                 * Whether this rate represents read or write is determined
+                 * by file type "fileid".
+                 */
+                u64 bps;
+        } val;
 };
 
 extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
                                      dev_t dev);
+extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
+                                     dev_t dev);
+extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
+                                     dev_t dev);
 
 typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
 typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
                                                 unsigned int weight);
+typedef void (blkio_update_group_read_bps_fn) (struct blkio_group *blkg,
+                                                u64 read_bps);
+typedef void (blkio_update_group_write_bps_fn) (struct blkio_group *blkg,
+                                                u64 write_bps);
 
 struct blkio_policy_ops {
         blkio_unlink_group_fn *blkio_unlink_group_fn;
         blkio_update_group_weight_fn *blkio_update_group_weight_fn;
+        blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
+        blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
 };
 
 struct blkio_policy_type {