debug/io-stats: Adding stat for weighted & unweighted average latency

Summary:
- Our current approach to measuring "average fop latency" is badly
  flawed in that it doesn't weight the FOPs correctly according to how
  many occurred in the time interval.  This makes Statisticians very
  sad.  This patch adds an internally computed weighted average
  latency which will be far more efficient to display via ODS, as well
  as having the benefit of not being complete nonsense.

Reviewers: kvigor, dph, sshreyas

Reviewed By: sshreyas

Change-Id: Ie3618f279b545610b7ed1a8482243fcc8dc53217
BUG: 1523353
Reviewed-on: https://review.gluster.org/18192
Reviewed-by: Shreyas Siravara <sshreyas@fb.com>
Smoke: Gluster Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Signed-off-by: Ana M. Neri <amnerip@fb.com>

0 files changed, 0 insertions, 0 deletions