Questions tagged [kernel]
Everything about Unix kernels: development, configuration, compilation, design, etc.
3,487
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Kernel config option CONFIG_VIRT_WIFI
So there's a module that is an virtual wifi device wrapper for ethernet controllers. The flag for configuring this in a kernel build is CONFIG_VIRT_WIFI. The typical usecase for this is if you're a ...
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Hibernation does not find enough memory despite nearly zero swap usage
I'm trying to diagnose an issue related to hibernation. I'm on a Lenovo Ideapad (AMD) running Manjaro and kernel 6.1.53-1-MANJARO. When I attempt a hibernate, I'm constantly getting errors about not ...
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Black screen at boot time after a kernel update/upgrade or a clean install
Yo there, I have been experiencing a black screen problem after a clean install, an update of the kernel or upgrade of the distribution (opensuse tumbleweed). Recently what it struck the issue was a ...
- 518
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21
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grub not adding newly installed kernel to list
I'm on an Arch system with LUKS and BRTFS and I recently installed linux-zen, but it doesn't show up anywhere in grub. I've tried grub-mkconfig -o /boot/grub/grub.cfg, but it does nothing, even though ...
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How to add linux-rt and linux-rt-lts to bootloader on Arch Linux?
Below is the list of linux packages installed on my Arch system.
$ pacman -Qsq 'linux' | grep -E '^linux*'
linux
linux-api-headers
linux-firmware
linux-hardened
linux-hardened-headers
linux-headers
...
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35
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My Ubuntu kernel config file does not recognizes all memory available to the system,but only half
The project that I've been working on since 2 years is to enable KVM (with the support of libvirt and virt-manager) on a recent version of Linux and of its kernel on the old but still nice ARM ...
- 495
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1
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33
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Kernel panic on boot, only when ethernet adapter connected
Hardware:
Late 2013 MacBook Pro Retina
16gb RAM, no swap space enabled
aftermarket 2TB SSD
Brand new Thunderbolt to Ethernet adapter
Software:
Fresh install of Ubuntu Server 22.04.3, with GNU/...
4
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1
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247
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Why does my system heavily use swap when there are 86 GB of RAM still usable?
This is not so much a performance problem as it is a desire to understand what is happening and how it works. I have a system with lots of resources, including 128 GB of RAM. What I have discovered (...
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2
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35
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uboot kernel and dtb calculation
What is the method to calculate these parameters in uboot ? :
bootm_low=0
bootm_size=7ff00000
fdt_addr_r=0x40000000
fdt_high=0x100000
fdt_size_r=0x400000
fdtcontroladdr=7bc971c0
kernel_addr_r=...
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Errors when trying to bring ethernet interface up on embedded Linux
I am trying to compile the Linux kernel (3.0.8, buildroot-gcc-12.3.0, ARMv7) to run on my IP camera.
eth0 is not able to get up.
At first, kernel boot just crashed at Starting network step:
Unable to ...
- 101
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CentOS 8 won't boot after kernel and nvidia drivers updated
After I updated kernel and installed nvidia drivers via official repository, system won't boot and all I see is an infinite aer message loop:
snd_hda_intel 0000:41:00.1: AER: aer_status: 0x00000001, ...
- 101
2
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How to debug a USB audio event that happens during boot?
I have a Topping D30Pro USB DAC which works (mostly) fine once logged in, but during boot (systemd), right around "Reached Target Sound Card", it starts outputting, what I'd have to guess, a ...
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VFS: cannot open root device "nvme1n1p4" or unknown-block & Kernel Panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
I was in the process of upgrading my Ubuntu 20.04 to 22.04. Unfortunately, I made an error during the upgrade process. I decided to restart the computer hoping it would fix the problem. Now I'm unable ...
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ip link set <network interface> up does not work reliably
Have embedded hardware running the 4.9 kernel and need to shut off an interface during a packet storm and that seems to work always using the command ip link set down but the up command to bring it ...
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Schedule IO problem via udev by-id
As the title, i'm trying to set the scheduler from boot by inserting the various disks using the udev rules. The problem is that indicating the disk by id (/dev/disk/by-id) in the udev rules (in the ...
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1
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Gamepad disconects after a while
I have bought some cheap generic usb gamepad (nubwo nj-25).
When I connect, it works for a while, until resting. And then throw errors.
Device info
I am using Linux 6.1.52 (NixOS)
Lenovo ThinkPad T14s ...
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1
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220
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Kernel 6.5.2 seems to have amdgpu crash on no-retry page fault
Before start: I replied to a thread on Arch Linux forum about similar issue (https://bbs.archlinux.org/viewtopic.php?id=284076), since I'm on Arch. I'm asking here to get more help and check if anyone ...
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CPU IDLE low as results of bad disks is it the case here
Low CPU IDLE can be caused by a variety of factors, including:Insufficient RAM or slow Hard Disk Drive
but in our RHEL server RAM memory have enough RAM but from dmesg we found couple errors about the ...
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What does it take to update kernel from 3.x to 5.X on qualcomm fsm99XX small cells platform
As of now qualcomm fsm99xx is on 3.10.84. 3.10.84 is given by qualcomm after a lot of extensive changes. we are trying to update it to 5.10 without support of qualcomm (as they don't support any more)....
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Linux Ubuntu Kernel crash: python: Corrupted page table
My system configuration:
Processor: 12th gen Core i7 12700K x 20
16 GB RAM
Not installed external GPU (No Graphics Card). All the GPU is from the processor itself (on chip)
Motherboard: Gigabyte ...
- 101
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2
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44
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Overlayfs not working on kernel 6.1.31 on a Gentoo VPS
I have a VPS with Gentoo on it and the kernel overlay fs is not working.
These are the kernel options related to overlay
compiled into the kernel
cat .config | grep -i overlay
...
- 111
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1
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34
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Linux Kernel (first) boot hangs/stalls - never prompts for login
I have built a custom kernel using the mainline source, latest version and this config.
I've created an image of Bullseye as suggester here
And then I ran it in QEMU (setting the relative environment ...
- 13
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1
answer
37
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uname -r showing linux-image version that is unsigned
My boot menu was full and then I tried to purge some older version of linux kernel with sudo dpkg --purge linux-image-... command. As initram-fs wasn't throwing error again and again I also tried some ...
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27
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What sets little endian state when launching a ppc64le Linux kernel on POWER CPU?
I've been doing some research on ppc64le Linux and am unclear on how the POWER CPU is set to little endian. As I understand it the machine and CPU state will run as big endian by default in firmware. ...
1
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1
answer
69
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Linux build with custom config using all RAM (8GB)?
I am trying to compile the mainline Linux kernel with a custom config. This one!
Running on a 64 bit system.
At the last step, when linking the Kernel, it fails because it goes OOM (error 137).
[...]
...
- 13
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1
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17
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Unable to find network card after executing mdev - s?
I am customizing a Linux system with a Linux kernel version of 6.4.0. I executed mdev -s in rcS and checked the startup print, which was also successful. When I entered the live environment, I saw ...
- 101
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88
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How to patch kernel to reduce VTIME gap for uart termios API?
I need help to find a kernel patch to get a VTIME from tty termios API lower than 100ms, in order to decrease gap inter char. It blocks read syscall until VTIME timeout.
Function n_tty_read() is the ...
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53
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Debian fails to boot on new kernel but runs fine under old kernel, how to troubleshoot?
Following a bump from Bullseye to Bookworm, Debian is unable to boot under its newest kernel. The new kernel 6.1.0-11 does not work at all. After displaying the booting to kernel message, there is no ...
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Centos7 Linux system hangs on boot
Here's what I did:
sudo yum update
A kernel update was not in the list; basic stuff and video drivers (problem ?)
dracut gave some error during update – do not recall specifics
At this point, /boot ...
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69
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starting init: /bin/sh exists but couldn't execute it (error -8)
I'am building Root filesystem for the Linux Kernel(6.2.11).
I want to compile the GNU Bash Shell(4.1) as the init program of the system. I built bash and installed it to the path /bin/, then linked /...
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178
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Ubuntu 22.04 unable to shutdown
I am having an issue, I can't shutdown my ubuntu laptop. Looks like it just gets stuck. I looked in multiple forums without luck and I thought maybe I could find help.
To be able to see the log I have ...
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Removing old kernels seemingly removed graphics driver, is it safe to reboot?
Removing old kernels seemingly removed graphics driver, is it safe to reboot?
While doing a routine sudo apt upgrade, I received a No space left on device error. It turned out that kernels kept ...
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failed: load btf from vmlinux: invalid argument make on CONFIG_DEBUG_INFO_BTF=y
I just got the following error when compiling linux-5.14.2.tar.gz and patch-5.14.2-rt21.patch
on CONFIG_DEBUG_INFO_BTF=y:
AS arch/x86/lib/iomap_copy_64.o
arch/x86/lib/iomap_copy_64.S: ...
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0
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39
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Getting an interfaces `valid_lft` programmatically
iproute2 can give back an interface's valid_lft which corresponds to the dhcp lease time left. See a truncated example output hereafter:
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue ...
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scsi timing out command, waited 300 seconds
I am booting rescue system on a server, which has defective HDD or controller.
The kernel boot process times out with following messages:
scsi timing out command, waited 300 seconds
eventually it ...
1
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0
answers
50
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Why do DisplayLink monitors stop working after suspend in 6.x kernel?
Symptoms
2 out of 4 monitors don't light up after suspend. This is a similar problem as this post but not quite the same.
Hardware
Dell XPS 9320 plus (i7-1280P)
UD22 Dock
4 monitors
OS
LinuxMint 21....
- 11
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54
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kernel memcpy actually copyed more bytes than the specified length
I have a kernel crash problem.
BUG: unable to handle page fault for address: ffff88812c410000
Stack information shows
ip_frag_next-->skb_copy_bits-->memcpy_orig+52
The analysis shows that the ...
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35
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Why the struct lsm_id is not present in linux kernel source tree
I am writing an LSM, and I am compiling it using my kernel 6.2.0-20-generic. When I browse the files in /lib/modules/6.2.0-20-generic/build, I can see that there is a struct named lsm_id. But When I ...
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Can't set charge_control_start_threshold and charge_control_end_threshold to distinct values
I'm trying to set battery thresholds on a Thinkpad laptop. I'm executing the following two commands:
echo 45 > /sys/class/power_supply/BAT1/charge_control_start_threshold
echo 50 > /sys/class/...
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1
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31
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kernel reports ACPI Error when bringing network card up or down
I get these errors in my logs, when bringing my network interface eth0 up or down, using ifup and ifdown:
kernel: e1000e 0000:00:19.0 eth0: NIC Link is Down
kernel: ACPI Error: Index value ...
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0
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21
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Manually update kernel `saved_entry` to the latest installed kernel after removing kernel (grub2-mkconfig didn't help)
I removed kernel version 6.4.4 and 6.4.6 using
Version="6.4.4-200.fc38"
sudo dnf remove kernel-{core,devel}-"${Version}"
Version="6.4.6-200.fc38"
sudo dnf remove kernel-{...
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`grub2-mkconfig`: skip a particular device for locating kernel
I updated grub as follows:
$ sudo grub2-mkconfig -o /boot/grub2/grub.cfg
Generating grub configuration file ...
File descriptor 3 (pipe:[240340]) leaked on vgs invocation. Parent PID 45665: grub2-...
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Using 1.69" spi display with NanoPi M1 Plus
for quite a few days I've been trying to get this TFT display to work with my NanoPi M1 Plus and I used the zip file provided in the link which actually worked but only for using it with the python ...
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28
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Mount bind point to incorrect NVMe device after power off/on device
I am developing an all-flash storage application. I found that mount bind has strange behavior on NVMe device power off/on.
Distro: SUSE Linux Enterprise Server 15 SP4 5.14.21-150400.24.46-default
...
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34
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Wifi - wpa_supplicant throwing no such device error
I am testing wifi in Ubuntu PC using wpa_supplicant utility. In PC, network device is listed as wlp3s0, when I tried to connect to wifi network using below command
wpa_supplicant -B -c /etc/...
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22
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PageUp/PageDown -- how to catch properly?
I am here on a tutorial to build a text editor.
I'm finding that on my macOS (it works on a Linux VM), even with raw mode enabled, I'm unable to intercept Page Up and Page Down, which are sent via fn-&...
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3
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Minimalistic ext4 filesystem without journal and other advanced features
I have a small "rescue" system (16 MB) that I boot into RAM as ramdisk. The initrd disk that I am preparing needs to be formatted. I think ext4 will do fine, but obviously, it doesn't make ...
2
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0
answers
166
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Failed to mount /sysroot
i get the follow error when try bootar a custom kernel:
[FAILED] Failed to mount /sysroot
[DEPEND] Dependency failed for initrd root file system.
[DEPEND] Dependency failed for Mounts configured in ...
0
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0
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22
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Frequency of Intra versus interprocess context switching
In a book I'm reading (from 2013) it says that, in the Linux Kernel, intraprocess switching is much more cheaper than interprocess switching, I guess, because the switching in a same CPU between two ...
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1
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77
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How to clear the /dev/kmsg ring buffer?
Is there a way for me to force clear the /dev/kmsg kernel ring buffer?
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