On 03/21/2017 11:56 AM, Omar Sandoval wrote:

From: Omar Sandoval <redacted>

This patchset generalizes the blk-stats infrastructure to allow users to
register a callback to be called at a given time with the statistics of
requests completed during that window. Writeback throttling and hybrid
polling are converted to the new infrastructure. The new Kyber I/O
scheduler uses this, as well (but it needs to be rebased on this v2).

The details are in patch 4, which is the actual conversion. Patches 1-3
are preparation cleanups.

Changes since v1:

- Now the user can subdivide stats into arbitrary buckets. Both in-tree
  users just do reads vs. writes, but we can extend poll based on
  request size in the future
- blk_stat_arm_callback() became blk_stat_activate_msecs() and
  blk_stat_activate_nsecs()
- The poll statistics are exposed in debugfs

Omar Sandoval (4):
  block: remove extra calls to wbt_exit()
  blk-stat: use READ and WRITE instead of BLK_STAT_{READ,WRITE}
  blk-stat: move BLK_RQ_STAT_BATCH definition to blk-stat.c
  blk-stat: convert to callback-based statistics reporting

Added for 4.12, thanks Omar. This is a nice improvement for the
writeback throttling as well, since solves the issues with
the stats and throttling having separate and unsynced windows.

-- 
Jens Axboe