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Log monitoring and analysis is an essential part of server or container infrastructure and is useful when handling complex applications. One of the popular logging solutions is the Elasticsearch, Fluentd, and Kibana (EFK) stack.

we have a network application in which we make netlink call and in the kernel-module we call register_netdev to create a network device we need. This works without any issues for small numbers.

When we create 8k network devices all at once, I could see it takes 2 minutes approx to complete, after which CPU usage continues to be high, mainly with many daemons named systemd-udevd and ifquery

root@NetwAA:~# pgrep -l systemd
1925 systemd-journal
1946 systemd-udevd
2130 systemd-logind
13381 systemd-udevd
13385 systemd-udevd
13393 systemd-udevd
13399 systemd-udevd
13405 systemd-udevd
13411 systemd-udevd
13415 systemd-udevd
13423 systemd-udevd
13428 systemd-udevd
13432 systemd-udevd
13441 systemd-udevd
13446 systemd-udevd
13452 systemd-udevd
13459 systemd-udevd
13462 systemd-udevd
13468 systemd-udevd
13475 systemd-udevd
13483 systemd-udevd
...

root@NetwAA:~# pgrep -l ifquery
13388 ifquery
13392 ifquery
13397 ifquery
13404 ifquery
13409 ifquery
13417 ifquery
...

top - 00:55:05 up 1:14, 2 users, load average: 70.09, 30.47, 12.17
Tasks: 462 total, 12 running, 450 sleeping, 0 stopped, 0 zombie
%Cpu(s): 19.0 us, 74.1 sy, 0.0 ni, 6.8 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 15937.0 total, 13024.0 free, 2283.3 used, 629.7 buff/cache
MiB Swap: 0.0 total, 0.0 free, 0.0 used. 13308.5 avail Mem

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1946 root 20 0 26412 11004 3896 R 99.3 0.1 2:22.81 systemd-u+
13551 root 20 0 7660 6820 1556 D 36.5 0.0 0:12.04 ifquery
13564 root 20 0 5812 4816 1404 R 15.6 0.0 0:10.69 ifquery
13656 root 20 0 2908 1968 1460 D 12.0 0.0 0:10.28 ifquery
13590 root 20 0 4096 3396 1564 D 11.6 0.0 0:10.29 ifquery
13711 root 20 0 3568 2856 1556 D 11.3 0.0 0:10.49 ifquery
13572 root 20 0 3964 3104 1540 D 11.0 0.0 0:12.23 ifquery
13784 root 20 0 4096 3236 1404 R 11.0 0.0 0:10.94 ifquery
13471 root 20 0 2380 1812 1564 D 10.6 0.0 0:10.91 ifquery
13640 root 20 0 8848 8020 1440 D 10.6 0.0 0:10.65 ifquery
13701 root 20 0 8056 7300 1512 D 10.0 0.0 0:11.42 ifquery
13630 root 20 0 3304 2592 1556 D 9.6 0.0 0:11.44 ifquery
13704 root 20 0 4492 3640 1548 D 9.6 0.0 0:10.96 ifquery
13392 root 20 0 9112 8304 1460 D 9.0 0.1 0:11.99 ifquery
13521 root 20 0 7660 6704 1440 D 9.0 0.0 0:12.84 ifquery
13770 root 20 0 8716 7768 1452 D 9.0 0.0 0:12.06 ifquery

High CPU usage by systemd-udevd and ifquery

after a long time: //about 10-15 mins

root@NetwAA:~# udevadm monitor
UDEV [538.005910] add /devices/virtual/net/xe9.924/queues/tx-0 (queues)
UDEV [538.011380] add /devices/virtual/net/xe9.934/queues/rx-0 (queues)
UDEV [538.248471] add /devices/virtual/net/xe9.933 (net)
UDEV [538.266858] add /devices/virtual/net/xe9.976 (net)
UDEV [538.358951] add /devices/virtual/net/xe9.933/queues/rx-0 (queues)
UDEV [538.359507] add /devices/virtual/net/xe9.933/queues/tx-0 (queues)
UDEV [538.359594] add /devices/virtual/net/xe9.936/queues/rx-0 (queues)
UDEV [538.360094] add /devices/virtual/net/xe9.934/queues/tx-0 (queues)
UDEV [538.360121] add /devices/virtual/net/xe9.936/queues/tx-0 (queues)
UDEV [538.609054] add /devices/virtual/net/xe9.954 (net)
UDEV [538.624835] add /devices/virtual/net/xe9.968 (net)
UDEV [538.797069] add /devices/virtual/net/xe9.932 (net)
UDEV [538.804163] add /devices/virtual/net/xe9.954/queues/rx-0 (queues)
UDEV [538.813290] add /devices/virtual/net/xe9.954/queues/tx-0 (queues)
UDEV [538.813778] add /devices/virtual/net/xe9.968/queues/rx-0 (queues)
UDEV [538.814202] add /devices/virtual/net/xe9.968/queues/tx-0 (queues)
UDEV [538.814664] add /devices/virtual/net/xe9.976/queues/rx-0 (queues)
UDEV [538.815270] add /devices/virtual/net/xe9.976/queues/tx-0 (queues)
UDEV [539.581034] add /devices/virtual/net/xe9.953 (net)
UDEV [539.634047] add /devices/virtual/net/xe9.978 (net)
...
...
UDEV [1277.422066] add /devices/virtual/net/xe9.7999/queues/rx-0 (queues)
UDEV [1277.425117] add /devices/virtual/net/xe9.7987 (net)
UDEV [1277.425660] add /devices/virtual/net/xe9.7987/queues/tx-0 (queues)
UDEV [1277.426005] add /devices/virtual/net/xe9.7987/queues/rx-0 (queues)
UDEV [1277.436997] add /devices/virtual/net/xe9.7996 (net)
UDEV [1277.437450] add /devices/virtual/net/xe9.7996/queues/rx-0 (queues)
UDEV [1277.437550] add /devices/virtual/net/xe9.7996/queues/tx-0 (queues)
UDEV [1277.473557] add /devices/virtual/net/xe9.7997 (net)
UDEV [1277.474560] add /devices/virtual/net/xe9.7997/queues/tx-0 (queues)
UDEV [1277.474615] add /devices/virtual/net/xe9.7997/queues/rx-0 (queues)


root@NetwAA:~#
root@NetwAA:~#
root@NetwAA:~# pgrep -l ifquery
root@NetwAA:~# pgrep -l systemd
1 systemd
1925 systemd-journal
1946 systemd-udevd
2130 systemd-logind
root@NetwAA:~#

what is happening in the background in kernel ?
why is the bottle-neck ? is it due to rtnl semaphore access ?

Version:next-20230525 (linux-next) Released:2023-05-25

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Hello, I am using a webdav server pro from the olive tree to mount my galaxy s8's internal storage. When I try to zip a folder using this command Code: find ."/sdcard/DCIM/Camera" -exec zip -0 -r "/home/ubuntu/Documents/test.zip" {} + I receive an error saying

zip I/O error: Bad address
zip error: Output file write failure (write error on zip file)

please see the attachment

Why?
Attached Thumbnails  

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I have an Asus ROG GL752VW with Linuxmint 20.3 Cinnamon. Everything has been fine since installing last year. All updates applied including kernels. Speaking of which, I just installed 5.15.0.72 a few days ago. It's an Intel 7265NGW, so the iwlwifi driver. Ethernet works fine.

Had been using the computer for a while the other day. Decided to connect via RJ-45 for some reason, and if my memory is working well, I also used the wifi simultaneouly. Shutdown at the end of the day, and as soon as I booted up this AM, no wifi, and Bluetooth will not connect automatically when i turn on my headset (previously it did).
So a few days ago when everything was fine, I updated the kernel, and I was using Ethernet for my connection. Those are the only things I remember doing differently. However, I tried reverting the kernel through the update manager to the previous one, but still no wifi.

Never used secure boot; so off.


Things I've tried and info:
1.
[CODE]inxi -Fxxxrz[CODE] =
Network: Device-1: Intel Wireless 7265 driver: iwlwifi v: kernel port: e000 bus ID: 02:00.0 chip ID: 8086:095a
IF: wlan0 state: down mac: <filter>
2.
Code: rfkill list && iwconfig && mokutil --sb-state =
0: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
1: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
lo no wireless extensions.

eth0 no wireless extensions.

wlan0 IEEE 802.11 ESSID:off/any
Mode:Managed Access Point: Not-Associated Tx-Power=-2147483648 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:off

tun0 no wireless extensions.

SecureBoot disabled
3.
After Code: ifconfig wlan0 up , it still says it's Code: down when using inxi.
4.
When putting the computer into airplane mode via Function + F2, the Bluetooth icon will put a red circle w/white 'x' on the BT icon in the taskbar. So I have not disabled via keyboard.
5.
Also, I wondered if the hardware was OK, so I booted my trusty SystemRescueCD USB stick, and yes, the wifi works fine. So something went awry in my Linuxmint config.
6.
Code: lspci -nnk | grep -iA3 net =

02:00.0 Network controller [0280]: Intel Corporation Wireless 7265 [8086:095a] (rev 59)
Subsystem: Intel Corporation Dual Band Wireless-AC 7265 [8086:5010]
Kernel driver in use: iwlwifi
Kernel modules: iwlwifi
--
03:00.1 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 12)
Subsystem: ASUSTeK Computer Inc. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [1043:200f]
Kernel driver in use: r8169
Kernel modules: r8169
7.
I looked at the power save:
Code: cat /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf
[connection]
wifi.powersave = 2 It had been 3, but I changed to 2, but still no wifi.
8.
Code: sudo tee /etc/modprobe.d/iwlwifi_opt.conf<<<"options iwlwifi 11n_disable=8 swcrypto=1"
sudo tee /etc/modprobe.d/iwlmvm_opt.conf<<<"options iwlmvm power_scheme=1" rebooted

Still no wifi
9.a.
Code: nmcli r wifi enabled
9.b.
Code: nmcli d wifi list IN-USE BSSID SSID MODE CHAN RATE SIGNAL BARS SECURITY
9.c.
nmcli d wifi connect mynet
Error: No network with SSID 'mynet' found.
10.
Code: sudo iwconfig wlan0 wlan0 IEEE 802.11 ESSID:off/any
Mode:Managed Access Point: Not-Associated Tx-Power=-2147483648 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Encryption key:off
Power Management:off
11.
Code: sudo iwlist wlan0 scan wlan0 Interface doesn't support scanning : Network is down

12.
Code: sudo dhclient -v wlan0 Listening on LPF/wlan0/4c:34:88:d7:d6:38
Sending on LPF/wlan0/4c:34:88:d7:d6:38
Sending on Socket/fallback
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 3 (xid=0xdbe42731)...

13.
Code: sudo ip link set wlan0 up 14.
Code: sudo ifup wlan0 Internet Systems Consortium DHCP Client 4.4.1
Copyright 2004-2018 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/wlan0/4c:34:88:d7:d6:38
Sending on LPF/wlan0/4c:34:88:d7:d6:38
Sending on Socket/fallback
Created duid "\000\001\000\001,\001\030\322L4\210\327\3268".
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 3 (xid=0xfa00780d)

Is there some .conf file that I need to check? Can the driver file be corrupt? I'm lost. Thanks.

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