[RFC PATCH 0/2] improve io scheduler callback triggering

Niklas Cassel
2021-08-27T12:41:29Z

From: Niklas Cassel <niklas.cassel@wdc.com>

Recently, there were some extra "dummy" data added into mq-deadline
rq->elv.priv, that was there for the solve purpose of working around
shortcomings in blk-mq (which called the scheduler callbacks even
for requests that bypassed the scheduler).

Fix blk-mq to behave in a more sane way with regards to scheduler
callback triggering, and remove the now unneeded rq->elv.priv magic.

BFQ should be able to perform a similar cleanup, and should be able
to drop this comment from the code:
https://github.com/torvalds/linux/blob/master/block/bfq-iosched.c#L6456-L6462

Considering that I'm quite unfamiliar with the BFQ code, I'd rather
someone who is a bit more familiar with BFQ performs that cleanup.

Kind regards,
Niklas

Niklas Cassel (2):
blk-mq: don't call callbacks for requests that bypassed the scheduler
Revert "mq-deadline: Fix request accounting"

block/blk-mq-sched.c | 20 ++++++++++++++++++++
block/blk-mq.c | 13 -------------
block/mq-deadline.c | 16 +++++-----------
include/linux/blkdev.h | 3 ++-
4 files changed, 27 insertions(+), 25 deletions(-)

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2.31.1