From: Jens Axboe <axboe@kernel.dk>
To: linux-block@vger.kernel.org
Subject: [PATCHSET 0/2] Add queue_is_busy helper
Date: Thu, 8 Nov 2018 08:42:14 -0700 [thread overview]
Message-ID: <20181108154216.23853-1-axboe@kernel.dk> (raw)
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(-)
--
Jens Axboe
next reply other threads:[~2018-11-08 15:42 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-08 15:42 Jens Axboe [this message]
2018-11-08 15:42 ` [PATCH 1/2] blk-mq-tag: change busy_iter_fn to return whether to continue or not Jens Axboe
2018-11-08 15:48 ` Mike Snitzer
2018-11-08 15:42 ` [PATCH 2/2] blk-mq: provide a helper to check if a queue is busy Jens Axboe
2018-11-08 15:49 ` Mike Snitzer
2018-11-08 15:54 ` Laurence Oberman
2018-11-08 15:58 ` Jens Axboe
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