[PATCH v4 0/2] fix inaccurate io_ticks

[PATCH v4 0/2] fix inaccurate io_ticks

[Weiping Zhang]

Hi,

This patchset include two patches,

01. block: fix inaccurate io_ticks
fix the io_ticks if start a new IO and there is no inflight IO before.
Please see the commit message of patch1 for more detail.

02. blk-mq: break more earlier when interate hctx
An optimization for blk_mq_queue_inflight and blk_mq_queue_inflight,
these two function only want to know if there is IO inflight and do
not care how many inflight IOs are there.
After this patch blk_mq_queue_inflight will stop interate other hctx
when find a inflight IO, blk_mq_part_is_in_inflight stop interate
other setbit/hctx when find a inflight IO.

Changes since v3:
 * add a parameter for blk_mq_queue_tag_busy_iter to break earlier
   when interate hctx of a queue, since blk_mq_part_is_in_inflight
   and blk_mq_queue_inflight do not care how many inflight IOs.

Changes since v2:
* use blk_mq_queue_tag_busy_iter framework instead of open-code.
* update_io_ticks before update inflight for __part_start_io_acct

Changes since v1:
* avoid iterate all tagset, return directly if find a set bit.
* fix some typo in commit message

Weiping Zhang (2):
  block: fix inaccurate io_ticks
  blk-mq: break more earlier when interate hctx

 block/blk-core.c       | 19 ++++++++++----
 block/blk-mq-tag.c     | 11 ++++++--
 block/blk-mq-tag.h     |  2 +-
 block/blk-mq.c         | 58 +++++++++++++++++++++++++++++++++++++++---
 block/blk-mq.h         |  1 +
 block/blk.h            |  1 +
 block/genhd.c          | 13 ++++++++++
 include/linux/blk-mq.h |  1 +
 8 files changed, 94 insertions(+), 12 deletions(-)

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2.18.4