Btrfs heavy I/O performance issues

Issues & Assistance
1 
garuda-inxi
System:
  Kernel: 5.18.10-zen1-1-zen arch: x86_64 bits: 64 compiler: gcc v: 12.1.0
    parameters: BOOT_IMAGE=/@/boot/vmlinuz-linux-zen
    root=UUID=53e270ad-dfd5-4874-a125-69d21ada6b8d rw rootflags=subvol=@
    rd.udev.log_priority=3 vt.global_cursor_default=0 loglevel=3
    sysrq_always_enabled=1 amdgpu.ppfeaturemask=0xffffffff nowatchdog
  Desktop: KDE Plasma v: 5.25.2 tk: Qt v: 5.15.5 info: latte-dock
    wm: kwin_wayland vt: 2 dm: SDDM Distro: Garuda Linux base: Arch Linux
Machine:
  Type: Desktop Mobo: ASRock model: X470 Taichi serial: <superuser required>
    UEFI: American Megatrends v: P4.86 date: 01/27/2022
Battery:
  Device-1: hidpp_battery_0 model: Logitech Wireless Mouse MX Master 3
    serial: <filter> charge: 100% (should be ignored) rechargeable: yes
    status: discharging
CPU:
  Info: model: AMD Ryzen 5 2600X bits: 64 type: MT MCP arch: Zen+ gen: 2
    built: 2018-21 process: GF 12nm family: 0x17 (23) model-id: 8 stepping: 2
    microcode: 0x800820D
  Topology: cpus: 1x cores: 6 tpc: 2 threads: 12 smt: enabled cache:
    L1: 576 KiB desc: d-6x32 KiB; i-6x64 KiB L2: 3 MiB desc: 6x512 KiB
    L3: 16 MiB desc: 2x8 MiB
  Speed (MHz): avg: 4108 high: 4125 min/max: 2200/3600 boost: enabled
    scaling: driver: acpi-cpufreq governor: performance cores: 1: 4108 2: 4101
    3: 4121 4: 4077 5: 4112 6: 4085 7: 4113 8: 4125 9: 4125 10: 4101 11: 4111
    12: 4120 bogomips: 86401
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm
  Vulnerabilities:
  Type: itlb_multihit status: Not affected
  Type: l1tf status: Not affected
  Type: mds status: Not affected
  Type: meltdown status: Not affected
  Type: mmio_stale_data status: Not affected
  Type: spec_store_bypass
    mitigation: Speculative Store Bypass disabled via prctl
  Type: spectre_v1
    mitigation: usercopy/swapgs barriers and __user pointer sanitization
  Type: spectre_v2
    mitigation: Retpolines, IBPB: conditional, STIBP: disabled, RSB filling
  Type: srbds status: Not affected
  Type: tsx_async_abort status: Not affected
Graphics:
  Device-1: AMD Navi 22 [Radeon RX 6700/6700 XT/6750 XT / 6800M]
    vendor: Gigabyte driver: amdgpu v: kernel arch: RDNA 2
    process: TSMC n7 (7nm) built: 2020-22 pcie: gen: 4 speed: 16 GT/s
    lanes: 16 ports: active: DP-1,HDMI-A-1 empty: DP-2,HDMI-A-2
    bus-ID: 0f:00.0 chip-ID: 1002:73df class-ID: 0300
  Display: wayland server: X.org v: 1.21.1.3 with: Xwayland v: 22.1.2
    compositor: kwin_wayland driver: X: loaded: amdgpu
    unloaded: modesetting,radeon alternate: fbdev,vesa gpu: amdgpu
    d-rect: 5888x2160 display-ID: 0
  Monitor-1: DP-1 pos: primary,left res: 2048x864 size: N/A modes: N/A
  Monitor-2: HDMI-A-1 pos: right res: 3840x2160 size: N/A modes: N/A
  OpenGL: renderer: AMD Radeon RX 6700 XT (navy_flounder LLVM 14.0.6 DRM
    3.46 5.18.10-zen1-1-zen)
    v: 4.6 Mesa 22.1.3 direct render: Yes
Audio:
  Device-1: AMD Navi 21/23 HDMI/DP Audio driver: snd_hda_intel v: kernel
    pcie: gen: 4 speed: 16 GT/s lanes: 16 bus-ID: 0f:00.1 chip-ID: 1002:ab28
    class-ID: 0403
  Sound Server-1: ALSA v: k5.18.10-zen1-1-zen running: yes
  Sound Server-2: sndio v: N/A running: no
  Sound Server-3: PulseAudio v: 16.1 running: no
  Sound Server-4: PipeWire v: 0.3.54 running: yes
Network:
  Device-1: Intel I211 Gigabit Network vendor: ASRock driver: igb v: kernel
    pcie: gen: 1 speed: 2.5 GT/s lanes: 1 port: d000 bus-ID: 09:00.0
    chip-ID: 8086:1539 class-ID: 0200
  IF: enp9s0 state: up speed: 1000 Mbps duplex: full mac: <filter>
Bluetooth:
  Device-1: Edimax Bluetooth Adapter type: USB driver: btusb v: 0.8
    bus-ID: 1-8:3 chip-ID: 7392:c611 class-ID: e001 serial: <filter>
  Report: bt-adapter ID: hci0 rfk-id: 0 state: up address: <filter>
Drives:
  Local Storage: total: 4.22 TiB used: 3.57 TiB (84.5%)
  SMART Message: Unable to run smartctl. Root privileges required.
  ID-1: /dev/nvme0n1 maj-min: 259:0 vendor: Samsung
    model: SSD 970 EVO 250GB size: 232.89 GiB block-size: physical: 512 B
    logical: 512 B speed: 31.6 Gb/s lanes: 4 type: SSD serial: <filter>
    rev: 2B2QEXE7 temp: 29.9 C scheme: GPT
  ID-2: /dev/nvme1n1 maj-min: 259:5 vendor: Samsung model: SSD 980 1TB
    size: 931.51 GiB block-size: physical: 512 B logical: 512 B
    speed: 31.6 Gb/s lanes: 4 type: SSD serial: <filter> rev: 1B4QFXO7
    temp: 38.9 C scheme: GPT
  ID-3: /dev/sda maj-min: 8:0 vendor: Seagate model: ST2000DX002-2DV164
    size: 1.82 TiB block-size: physical: 4096 B logical: 512 B speed: 6.0 Gb/s
    type: HDD rpm: 7200 serial: <filter> rev: CC41 scheme: GPT
  ID-4: /dev/sdb maj-min: 8:16 type: USB vendor: Western Digital
    model: WD10EURX-63UY4Y0 size: 931.51 GiB block-size: physical: 4096 B
    logical: 512 B type: HDD rpm: 5400 serial: <filter> scheme: GPT
  ID-5: /dev/sdd maj-min: 8:48 type: USB vendor: Generic
    model: STORAGE DEVICE size: 366.82 GiB block-size: physical: 512 B
    logical: 512 B type: N/A serial: <filter> rev: 1532 scheme: MBR
  SMART Message: Unknown USB bridge. Flash drive/Unsupported enclosure?
Partition:
  ID-1: / raw-size: 931.22 GiB size: 931.22 GiB (100.00%)
    used: 756.8 GiB (81.3%) fs: btrfs dev: /dev/nvme1n1p2 maj-min: 259:7
  ID-2: /boot/efi raw-size: 300 MiB size: 299.4 MiB (99.80%)
    used: 16.3 MiB (5.5%) fs: vfat dev: /dev/nvme1n1p1 maj-min: 259:6
  ID-3: /home raw-size: 931.22 GiB size: 931.22 GiB (100.00%)
    used: 756.8 GiB (81.3%) fs: btrfs dev: /dev/nvme1n1p2 maj-min: 259:7
  ID-4: /var/log raw-size: 931.22 GiB size: 931.22 GiB (100.00%)
    used: 756.8 GiB (81.3%) fs: btrfs dev: /dev/nvme1n1p2 maj-min: 259:7
  ID-5: /var/tmp raw-size: 931.22 GiB size: 931.22 GiB (100.00%)
    used: 756.8 GiB (81.3%) fs: btrfs dev: /dev/nvme1n1p2 maj-min: 259:7
Swap:
  Kernel: swappiness: 133 (default 60) cache-pressure: 100 (default)
  ID-1: swap-1 type: zram size: 31.27 GiB used: 3.89 GiB (12.4%)
    priority: 100 dev: /dev/zram0
Sensors:
  System Temperatures: cpu: 51.6 C mobo: 38.0 C gpu: amdgpu temp: 57.0 C
    mem: 60.0 C
  Fan Speeds (RPM): cpu: 2054 fan-1: 0 fan-3: 0 fan-4: 0 fan-5: 0
    gpu: amdgpu fan: 0
  Power: 12v: N/A 5v: N/A 3.3v: 3.25 vbat: 3.28 gpu: amdgpu watts: 31.00
Info:
  Processes: 446 Uptime: 2h 10m wakeups: 3 Memory: 31.27 GiB
  used: 11.04 GiB (35.3%) Init: systemd v: 251 default: graphical
  tool: systemctl Compilers: gcc: 12.1.0 clang: 14.0.6 Packages: 2427
  pacman: 2409 lib: 590 flatpak: 18 Shell: fish v: 3.4.1 default: Bash
  v: 5.1.16 running-in: alacritty inxi: 3.3.19
Garuda (2.6.4-2):
  System install date:     2022-05-22
  Last full system update: 2022-07-10
  Is partially upgraded:   No
  Relevant software:       NetworkManager
  Windows dual boot:       Probably (Run as root to verify)
  Snapshots:               Snapper
  Failed units:

So ever since I started using garuda I have noticed performance issues whenever there is high I/O usage such as downloading a game copying a big file etc..
Is this a limitation of btrfs? I didn't notice the same performance issue when I briefly installed ubuntu on this same disk to troubleshoot some other issues I was having.

2

Check with htop if baloo (or similar) is in action.

Most of the time I have heavy use from Dolphin.

2 Likes
3

baloo is always the first thing i disable whenever I install kde. yeah its usually dolphin that has heavy usage from some copy operation. I didn't really pay attention to this until i switched to ubuntu for a bit and noticed way better system responsiveness. Which is why i was wondering if btrfs is inherently less responsive the ext4 or something

Something I did try just now is changing the cpu scheduler from performance to schedutil which seems to help with responsiveness a bit?

4

Is this happening when performing copy operations to an external USB drive?

Does this happen when performing a copy operation from the terminal as well?

I would test different kernels and I/O schedulers for improvements.

2 Likes
5

wow did not expect schedutil to make such a difference from performance. it seems to be spreading out the load more rather than just push one core.

I'm testing with multiple I/O operations one in the terminal merging some split files I needed to merge and another copying some files to a usb . while also syncing my docs to a cloud backup. cpu load is high as expected on most cores but the responsiveness is butter smooth.

maybe the schedutil cpu governor should be made the default if its not?

6

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