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Most of logic board today comes with an integrated graphic card. Once a CUDA device is plugged in, X11 will recognize there is a new VGA device and configure it for X11 with memory allocations.

Blow is an example nvidia-smi output showing Xorg (X11) and gnome environment are using a large chunk of the GPU memory.

+—————————————————————————–+
| NVIDIA-SMI 470.182.03   Driver Version: 470.182.03   CUDA Version: 11.4     |
|——————————-+———————-+———————-+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|                               |                      |               MIG M. |
|===============================+======================+======================|
|   0  NVIDIA GeForce …  Off  | 00000000:01:00.0  On |                  N/A |
|  0%   48C    P8    19W / 180W |   1201MiB /  8110MiB |     13%      Default |
|                               |                      |                  N/A |
+——————————-+———————-+———————-++—————————————————————————–+
| Processes:                                                                  |
|  GPU   GI   CI        PID   Type   Process name                  GPU Memory |
|        ID   ID                                                   Usage      |
|=============================================================================|
|    0   N/A  N/A      1738      G   /usr/lib/xorg/Xorg                246MiB |
|    0   N/A  N/A      2033      G   /usr/bin/gnome-shell                7MiB |
|    0   N/A  N/A      2812      G   /usr/lib/xorg/Xorg                514MiB |
|    0   N/A  N/A      2942      G   /usr/bin/gnome-shell              169MiB |
|    0   N/A  N/A    321543      G   …NiYQ%3D%3D&browser=chrome       36MiB |
|    0   N/A  N/A    321587      G   …/debug.log –shared-files        5MiB |
|    0   N/A  N/A    458830      G   …390373760644109118,131072      115MiB |
|    0   N/A  N/A    458872      G   …veSuggestionsOnlyOnDemand       78MiB |
+—————————————————————————–+

If you want to use the CUDA device for computing, better free up the GPU memory. Here is a way to do it.

First, find the address of the device you want to use. You can change “Display” to “VGA” to list all the devices can be used to control the monitor.

$ lspci |grep Display
00:02.0 Display controller: Intel Corporation UHD Graphics 630 (Desktop)

Then edit or create /etc/X11/xorg.conf. Note: “sudo” privilege is required here.

Section "Device"
    Identifier      "intel"
    Driver          "intel"
    BusId           "PCI:0:2:0"
EndSection

Section "Screen"
    Identifier      "intel"
    Device          "intel"
EndSection

Restart the X11 environment or reboot, and you will see that GPU memory is now freed up and can all be used for CUDA computing.

~$ nvidia-smi
Mon May 1 11:03:18 2023
+—————————————————————————–+
| NVIDIA-SMI 470.182.03 Driver Version: 470.182.03 CUDA Version: 11.4 |
|——————————-+———————-+———————-+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
| | | MIG M. |
|===============================+======================+======================|
| 0 NVIDIA GeForce … Off | 00000000:01:00.0 Off | N/A |
| 0% 55C P8 10W / 180W | 2MiB / 8119MiB | 0% Default |
| | | N/A |
+——————————-+———————-+———————-+

+—————————————————————————–+
| Processes: |
| GPU GI CI PID Type Process name GPU Memory |
| ID ID Usage |
|=============================================================================|
| No running processes found |
+—————————————————————————–+

Controlling network access of a specific device to a router using web interface is a pain. Thanks to Mathieu Velten, who developed pynetgear, a Python package that supports scripting Netgear router, by reverse engineering the Netgear Genie App.

I wrote the following code utilizing the pynetgear package to turn on (Allow) and off (Block) network access for a specific device to my router.

#!/usr/bin/env python
import sys
import time
import click
from pynetgear import Netgear


class NetgearManager:
    """
    Netgear Router Manager
    """
    def __init__(self, pwd):
        self.session = Netgear(password=pwd)

    def search_connected_device_by_name(self, name):
        found = []
        for device in self.session.get_attached_devices():
            if device.name == name:
                found.append(device)
        if len(found) >= 0:
            return found
        return None

    def get_device_status_by_name(self, name):
        devices = self.search_connected_device_by_name(name)
        if len(devices) > 1:
            print(f'More than one device has the name {name}', file=sys.stderr)
            for d in devices:
                print(d.ip, d.type, d.mac, d.allow_block_device)
        return False

    def set_device_status_by_name(self, name, status_code, delay):
        assert status_code in ['Allow', 'Block']
        devices = self.search_connected_device_by_name(name)
        if len(devices)==1:
            mac_address = devices[0].mac
            return self.set_device_status_by_mac(self, mac_address, status_code, delay)
        elif len(devices)>1:
            print(f'More than one device has the name {name}', file=sys.stderr)
            for d in devices:
                print(d.ip, d.type, d.mac, d.allow_or_block, file=sys.stderr)
        return False

    def set_device_status_by_mac(self, mac, status_code, delay):
        if delay > 0:
            time.sleep(delay)
        return self.session.allow_block_device(mac, device_status=status_code)

@click.group()
def cli():
    pass

@click.command()
@click.option('--password', prompt=True, hide_input=True, confirmation_prompt=False, help='Netgear outer admmin password')
@click.option('--name', help='Device name')
@click.option('--mac', default=None, help='Device MAC address')
@click.option('--status', help='Status: Allow or Block')
@click.option('--delay', default=0, help='Time delay in minutes')
def switch(password, name, mac, status, delay):
    manager = NetgearManager(password)
    delay *= 60                 # minutes to seconds
    if mac:
        result = manager.set_device_status_by_mac(mac, status, delay)
    else:
        result = manager.set_device_status_by_name(name, status, delay)
    if not result:
        msg = f'Cannot switch device {name} status to {status}'
        print(msg, file=sys.stderr)

@click.command()
@click.option('--password', prompt=True, hide_input=True, confirmation_prompt=False, help='Netgear outer admmin password')
def show(password):
    manager = NetgearManager(password)
    devices = []
    for idx, dev in enumerate(manager.session.get_attached_devices()):
        print(str(idx), dev.name, dev.ip, dev.type, dev.mac, dev.allow_or_block)

cli.add_command(switch)
cli.add_command(show)

if __name__ == '__main__':
    cli()