block: store elevator state in request

Browse source

Add an rq private RQF_ELV flag, which tells the block layer that this
request was initialized on a queue that has an IO scheduler attached.
This allows for faster checking in the fast path, rather than having to
deference rq->q later on.

Elevator switching does full quiesce of the queue before detaching an
IO scheduler, so it's safe to cache this in the request itself.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

...

This commit is contained in:

Jens Axboe 2021-10-15 09:44:38 -06:00

parent 90b8faa0e8

commit 2ff0682da6

3 changed files with 29 additions and 20 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

13

block/blk-mq-sched.h

View file

20

block/blk-mq.c

View file

2

include/linux/blk-mq.h

View file