blkio: Increment the blkio cgroup stats for real now

We also add start_time_ns and io_start_time_ns fields to struct request
here to record the time when a request is created and when it is
dispatched to device. We use ns uints here as ms and jiffies are
not very useful for non-rotational media.

Signed-off-by: Divyesh Shah<dpshah@google.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 19 insertions, 1 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6690e8bae7bb..f3fff8bf85ee 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -194,7 +194,10 @@ struct request {
 
         struct gendisk *rq_disk;
         unsigned long start_time;
-
+#ifdef CONFIG_BLK_CGROUP
+        unsigned long long start_time_ns;
+        unsigned long long io_start_time_ns;    /* when passed to hardware */
+#endif
         /* Number of scatter-gather DMA addr+len pairs after
          * physical address coalescing is performed.
          */
@@ -1196,6 +1199,21 @@ static inline void put_dev_sector(Sector p)
 struct work_struct;
 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
 
+#ifdef CONFIG_BLK_CGROUP
+static inline void set_start_time_ns(struct request *req)
+{
+        req->start_time_ns = sched_clock();
+}
+
+static inline void set_io_start_time_ns(struct request *req)
+{
+        req->io_start_time_ns = sched_clock();
+}
+#else
+static inline void set_start_time_ns(struct request *req) {}
+static inline void set_io_start_time_ns(struct request *req) {}
+#endif
+
 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
         MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \