[PATCH v5 0/2] nvmet: add cgroup_id to charge namespace I/O to a cgroup
From: Peng Yu
Date: Sat Sep 26 2026 - 02:36:33 EST
Scenario:
* Create multiple nvmet subsystems/namespaces.
* The namespaces are backed by different LVM logical volumes.
* Some of the logical volumes share the same physical volumes.
* The subsystems are exported to different users.
* We should provide each user a specific iops/bps quota, thus a noisy
neighbor won't impact the performance of other logical volumes.
Test:
1 Load kernel modules.
sudo modprobe brd rd_nr=2 rd_size=1048576
sudo modprobe nvmet
sudo modprobe nvmet_tcp
sudo modprobe nvme_tcp
2 The two brd devices are used for a bdev backed namespace and a file
backed namespace, remember their major/minor.
lsblk --noheadings --nodeps --output NAME,MAJ:MIN,SIZE /dev/ram0 /dev/ram1
ram0 1:0 1G
ram1 1:1 1G
3 Enable the io controller and create two cgroups, one for the bdev
backed namespace, another for the file backed namespace.
echo "+io" | sudo tee /sys/fs/cgroup/cgroup.subtree_control
sudo mkdir -p /sys/fs/cgroup/nvmet-bdev
sudo mkdir -p /sys/fs/cgroup/nvmet-file
4 Create a file system and a file on ram0.
sudo mkfs.ext4 /dev/ram0
sudo mkdir -p /mnt/nvmet-file
sudo mount -o noatime /dev/ram0 /mnt/nvmet-file
sudo dd if=/dev/zero of=/mnt/nvmet-file/ns.img bs=1M count=512 oflag=direct
5 Create the bdev backed subsystem and namespace.
sudo mkdir -p /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1
echo 1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/attr_allow_any_host
echo /dev/ram1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1/device_path
stat -c %i /sys/fs/cgroup/nvmet-bdev | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1/cgroup_id
echo 1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1/enable
6 Create the file backed subsystem and namespace.
sudo mkdir -p /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1
echo 1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/attr_allow_any_host
echo /mnt/nvmet-file/ns.img | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1/device_path
stat -c %i /sys/fs/cgroup/nvmet-file | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1/cgroup_id
echo 1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1/enable
7 Export the two subsystems to 127.0.0.1.
sudo mkdir -p /sys/kernel/config/nvmet/ports/1
echo ipv4 | sudo tee /sys/kernel/config/nvmet/ports/1/addr_adrfam
echo tcp | sudo tee /sys/kernel/config/nvmet/ports/1/addr_trtype
echo 127.0.0.1 | sudo tee /sys/kernel/config/nvmet/ports/1/addr_traddr
echo 4420 | sudo tee /sys/kernel/config/nvmet/ports/1/addr_trsvcid
sudo ln -s /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev /sys/kernel/config/nvmet/ports/1/subsystems/nqn.2026-09.io.test01:bdev
sudo ln -s /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file /sys/kernel/config/nvmet/ports/1/subsystems/nqn.2026-09.io.test01:file
8 Connect the two subsystems from 127.0.0.1.
sudo nvme connect -t tcp -a 127.0.0.1 -s 4420 -n nqn.2026-09.io.test01:bdev
sudo nvme connect -t tcp -a 127.0.0.1 -s 4420 -n nqn.2026-09.io.test01:file
sudo udevadm settle
9 Set riops to 20k and run fio.
echo "1:1 riops=20000 wiops=max rbps=max wbps=max" | sudo tee /sys/fs/cgroup/nvmet-bdev/io.max
echo "1:0 riops=20000 wiops=max rbps=max wbps=max" | sudo tee /sys/fs/cgroup/nvmet-file/io.max
sudo fio --name=t --filename=/dev/nvme0n1 --rw=randread --bs=4k --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
read: IOPS=20.0k, BW=78.1MiB/s (81.9MB/s)(781MiB/10001msec)
sudo fio --name=t --filename=/dev/nvme1n1 --rw=randread --bs=4k --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
read: IOPS=20.0k, BW=78.2MiB/s (82.0MB/s)(782MiB/10001msec)
10 Set rbps to 100M and run fio.
echo "1:1 riops=max wiops=max rbps=104857600 wbps=max" | sudo tee /sys/fs/cgroup/nvmet-bdev/io.max
echo "1:0 riops=max wiops=max rbps=104857600 wbps=max" | sudo tee /sys/fs/cgroup/nvmet-file/io.max
sudo fio --name=t --filename=/dev/nvme0n1 --rw=read --bs=1M --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
read: IOPS=97, BW=100MiB/s (105MB/s)(1041MiB/10399msec)
sudo fio --name=t --filename=/dev/nvme1n1 --rw=read --bs=1M --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
read: IOPS=97, BW=100MiB/s (105MB/s)(1031MiB/10299msec)
11 Set wiops to 20k and run fio.
echo "1:1 riops=max wiops=20000 rbps=max wbps=max" | sudo tee /sys/fs/cgroup/nvmet-bdev/io.max
echo "1:0 riops=max wiops=20000 rbps=max wbps=max" | sudo tee /sys/fs/cgroup/nvmet-file/io.max
sudo fio --name=t --filename=/dev/nvme0n1 --rw=randwrite --bs=4k --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
write: IOPS=20.0k, BW=78.1MiB/s (81.9MB/s)(781MiB/10001msec); 0 zone resets
sudo fio --name=t --filename=/dev/nvme1n1 --rw=randwrite --bs=4k --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
write: IOPS=20.0k, BW=78.1MiB/s (81.9MB/s)(781MiB/10002msec); 0 zone resets
12 Set wbps to 100M and run fio.
echo "1:1 riops=max wiops=max rbps=max wbps=104857600" | sudo tee /sys/fs/cgroup/nvmet-bdev/io.max
echo "1:0 riops=max wiops=max rbps=max wbps=104857600" | sudo tee /sys/fs/cgroup/nvmet-file/io.max
sudo fio --name=t --filename=/dev/nvme0n1 --rw=write --bs=1M --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
write: IOPS=97, BW=100MiB/s (105MB/s)(1032MiB/10307msec); 0 zone resets
sudo fio --name=t --filename=/dev/nvme1n1 --rw=write --bs=1M --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
write: IOPS=97, BW=100MiB/s (105MB/s)(1033MiB/10296msec); 0 zone resets
13 Cleanup the environment.
sudo nvme disconnect -n nqn.2026-09.io.test01:bdev
sudo nvme disconnect -n nqn.2026-09.io.test01:file
sudo udevadm settle
sudo rm -f /sys/kernel/config/nvmet/ports/1/subsystems/nqn.2026-09.io.test01:bdev
sudo rm -f /sys/kernel/config/nvmet/ports/1/subsystems/nqn.2026-09.io.test01:file
sudo rmdir /sys/kernel/config/nvmet/ports/1
echo 0 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1/enable
sudo rmdir /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1
sudo rmdir /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev
echo 0 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1/enable
sudo rmdir /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1
sudo rmdir /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file
sudo umount /mnt/nvmet-file
sudo rmdir /mnt/nvmet-file
sudo modprobe -r brd
sudo rmdir /sys/fs/cgroup/nvmet-bdev
sudo rmdir /sys/fs/cgroup/nvmet-file
sudo rmmod nvme_tcp
sudo rmmod nvmet_tcp
sudo rmmod nvmet
Peng Yu (2):
cgroup: export cgroup_e_css()
nvmet: add cgroup_id to charge namespace I/O to a cgroup
drivers/nvme/target/configfs.c | 47 ++++++++++++++++++++++++
drivers/nvme/target/core.c | 54 ++++++++++++++++++++++++++++
drivers/nvme/target/io-cmd-bdev.c | 18 +++++++++-
drivers/nvme/target/io-cmd-file.c | 21 +++++++++--
drivers/nvme/target/nvmet.h | 59 +++++++++++++++++++++++++++++++
drivers/nvme/target/zns.c | 5 +++
kernel/cgroup/cgroup.c | 1 +
7 files changed, 202 insertions(+), 3 deletions(-)
base-commit: d9cc476535d29a44df3f2aa3b14af9a833fddf90
--
2.53.0