[PATCH 0/5] Latency cleanups

From: Vincent Fu <vincent.fu@samsung.com>
To: "axboe@kernel.dk" <axboe@kernel.dk>,
	"fio@vger.kernel.org" <fio@vger.kernel.org>
Cc: Vincent Fu <vincent.fu@samsung.com>
Subject: [PATCH 0/5] Latency cleanups
Date: Tue, 14 Jun 2022 15:58:29 +0000	[thread overview]
Message-ID: <20220614155822.307771-1-vincent.fu@samsung.com> (raw)
In-Reply-To: CGME20220614155830uscas1p1e1d6595b29fb6960b405d5b295a32ffc@uscas1p1.samsung.com

Jens, here are a few latency cleanup patches. The main improvement is to
avoid recording issue_time twice for the ioengines that record
issue_time themselves when their commit hook is called. Recording
issue_time twice underestimates clat since the first issue_time value is
used for slat and then the later second issue_time is used when
calculating clat.

I'm not able to test the rdma and librpma ioengines but the fix for
libaio and io_uring appears to work properly.

Vincent Fu (5):
  ioengines: add helper for trims with async ioengines
  ioengines: don't record issue_time if ioengines already do it
  HOWTO: improve description of latency measures
  ioengines: update last_issue if we set issue_time
  ioengines: clean up latency accounting for 3 ioengines

 HOWTO.rst               | 29 ++++++++++++++++-----------
 engines/io_uring.c      | 13 ++++++++++--
 engines/libaio.c        |  9 ++++++++-
 engines/librpma_apm.c   |  2 +-
 engines/librpma_fio.c   |  9 ++++++++-
 engines/librpma_gpspm.c |  2 +-
 engines/rdma.c          |  9 ++++++++-
 ioengines.c             | 44 ++++++++++++++++++++++++-----------------
 ioengines.h             |  2 ++
 9 files changed, 83 insertions(+), 36 deletions(-)

-- 
2.25.1