[v3,0/2] Historical Service Time Path Selector

Message

Gabriel Krisman Bertazi April 30, 2020, 8:48 p.m. UTC

Hi,

This is the third version of HST considering the review by Mike
Snitzer.  This version drops the encapsulation patches and passes the
parameter directly to end_io.  It also uses jiffies_to_nsecs directly in
dm_start_time_ns_from_clone, instead of converting to msecs in an
intermediary step.

This didn't show any regressions compared to the benchmark I presented
on previous version:

v2: https://www.redhat.com/archives/dm-devel/2020-April/msg00270.html
v1: https://www.redhat.com/archives/dm-devel/2020-April/msg00176.html

This was tested primarily on a Google cloud SAN with real data and usage
patterns and with artificial benchmarks using fio.

Gabriel Krisman Bertazi (1):
  md: mpath: Pass IO start time to path selector

Khazhismel Kumykov (1):
  md: mpath: Add Historical Service Time Path Selector

 drivers/md/Kconfig                      |  11 +
 drivers/md/Makefile                     |   1 +
 drivers/md/dm-historical-service-time.c | 561 ++++++++++++++++++++++++
 drivers/md/dm-mpath.c                   |   9 +-
 drivers/md/dm-path-selector.h           |   2 +-
 drivers/md/dm-queue-length.c            |   2 +-
 drivers/md/dm-service-time.c            |   2 +-
 drivers/md/dm.c                         |  10 +
 include/linux/device-mapper.h           |   2 +
 9 files changed, 594 insertions(+), 6 deletions(-)
 create mode 100644 drivers/md/dm-historical-service-time.c