On Sun, Sep 04, 2022 at 02:17:33PM -0600, Jens Axboe wrote:
On 9/4/22 11:01 AM, Kanchan Joshi wrote:
On Sat, Sep 03, 2022 at 11:00:43AM -0600, Jens Axboe wrote:
On 9/2/22 3:25 PM, Jens Axboe wrote:
On 9/2/22 1:32 PM, Jens Axboe wrote:
On 9/2/22 12:46 PM, Kanchan Joshi wrote:
On Fri, Sep 02, 2022 at 10:32:16AM -0600, Jens Axboe wrote:
On 9/2/22 10:06 AM, Jens Axboe wrote:
On 9/2/22 9:16 AM, Kanchan Joshi wrote:
Hi,
Currently uring-cmd lacks the ability to leverage the pre-registered
buffers. This series adds the support in uring-cmd, and plumbs
nvme passthrough to work with it.
Using registered-buffers showed peak-perf hike from 1.85M to 2.17M IOPS
in my setup.
Without fixedbufs
*****************
# taskset -c 0 t/io_uring -b512 -d128 -c32 -s32 -p0 -F1 -B0 -O0 -n1 -u1 /dev/ng0n1
submitter=0, tid=5256, file=/dev/ng0n1, node=-1
polled=0, fixedbufs=0/0, register_files=1, buffered=1, QD=128
Engine=io_uring, sq_ring=128, cq_ring=128
IOPS=1.85M, BW=904MiB/s, IOS/call=32/31
IOPS=1.85M, BW=903MiB/s, IOS/call=32/32
IOPS=1.85M, BW=902MiB/s, IOS/call=32/32
^CExiting on signal
Maximum IOPS=1.85M
With the poll support queued up, I ran this one as well. tldr is:
bdev (non pt)??? 122M IOPS
irq driven??? 51-52M IOPS
polled??????? 71M IOPS
polled+fixed??? 78M IOPS
Followup on this, since t/io_uring didn't correctly detect NUMA nodes
for passthrough.
With the current tree and the patchset I just sent for iopoll and the
caching fix that's in the block tree, here's the final score:
polled+fixed passthrough??? 105M IOPS
which is getting pretty close to the bdev polled fixed path as well.
I think that is starting to look pretty good!
Great! In my setup (single disk/numa-node), current kernel shows-
Block MIOPS
***********
command:t/io_uring -b512 -d128 -c32 -s32 -p0 -F1 -B0 -P1 -n1 /dev/nvme0n1
plain: 1.52
plain+fb: 1.77
plain+poll: 2.23
plain+fb+poll: 2.61
Passthru MIOPS
**************
command:t/io_uring -b512 -d128 -c32 -s32 -p0 -F1 -B0 -O0 -P1 -u1 -n1 /dev/ng0n1
plain: 1.78
plain+fb: 2.08
plain+poll: 2.21
plain+fb+poll: 2.69
Interesting, here's what I have:
Block MIOPS
============
plain: 2.90
plain+fb: 3.0
plain+poll: 4.04
plain+fb+poll: 5.09
Passthru MIPS
=============
plain: 2.37
plain+fb: 2.84
plain+poll: 3.65
plain+fb+poll: 4.93
This is a gen2 optane
same. Do you see same 'FW rev' as below?
# nvme list
Node SN Model Namespace Usage Format FW Rev
--------------------- -------------------- ---------------------------------------- --------- -------------------------- ---------------- --------
/dev/nvme0n1 PHAL11730018400AGN INTEL SSDPF21Q400GB 1 400.09 GB / 400.09 GB 512 B + 0 B L0310200
, it maxes out at right around 5.1M IOPS. Note that
I have disabled iostats and merges generally in my runs:
echo 0 > /sys/block/nvme0n1/queue/iostats
echo 2 > /sys/block/nvme0n1/queue/nomerges
which will impact block more than passthru obviously, particularly
the nomerges. iostats should have a similar impact on both of them (but
I haven't tested either of those without those disabled).
bit improvment after disabling, but for all entries.
block
=====
plain: 1.6
plain+FB: 1.91
plain+poll: 2.36
plain+FB+poll: 2.85
passthru
========
plain: 1.9
plain+FB: 2.2
plain+poll: 2.4
plain+FB+poll: 2.9
Maybe there is something about my kernel-config that prevents from
reaching to expected peak (i.e. 5.1M). Will check more.
