mbox series

[PATCHSET,0/2] Add queue_is_busy helper

Message ID 20181108154216.23853-1-axboe@kernel.dk (mailing list archive)
Headers show
Series Add queue_is_busy helper | expand

Message

Jens Axboe Nov. 8, 2018, 3:42 p.m. UTC 
DM currently uses atomic inc/dec to maintain a busy count of
IO on a given device. For the dm-mq path, we can replace this
with helper that just checks the state of the tags on the device.

First patch is a prep patch that allows the iteration helpers
to return true/false, like we support internally in sbitmap.
For a busy check we don't care about how many requests are
busy, just if some are or not. Hence we can stop iterating
tags as soon as we find one that is allocated.


 block/blk-mq-debugfs.c |  4 +++-
 block/blk-mq-tag.c     |  4 ++--
 block/blk-mq.c         | 38 +++++++++++++++++++++++++++++++++-----
 include/linux/blk-mq.h |  6 ++++--
 4 files changed, 42 insertions(+), 10 deletions(-)