Questions tagged [linux-kernel]
Questions about Linux kernel and Linux kernel related topics eg. implementation details such as system calls, kernel customization, etc. For Linux user space topics which do not involve kernel details, [linux] or distribution tag are more suitable.
3,729 questions
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Intel Core Ultra 9 275HX throttles to ~1.8 GHz under sustained load on Linux (Lenovo Legion 7)
Hardware / OS:
Laptop: Lenovo Legion 7 16IAX10
BIOS: RXCN23WW (from sudo dmidecode -s bios-version)
CPU: Intel(R) Core™ Ultra 9 275HX (from lscpu)
Distro + kernel: EndeavourOS / Linux 6.17.2-arch1-1
...
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Intel Core Ultra 9 275HX + Linux: How’s the performance? [closed]
Has anyone successfully run Linux on an Intel Core Ultra 9 275HX without throttling or performance issues? (I'm using Lenovo Legion 7 16IAX10)
If so, which distro, kernel version, and settings (CPU ...
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What is the best way to detect busy CPU cores for blk-mq request steering in Linux kernel?
I am trying to implement request steering in Linux kernel’s blk-mq layer to distribute I/O requests across CPU cores based on load. My goal is to redirect requests from busy cores to less busy ones to ...
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What is the cost of listening on ports?
If you would open a listening socket on every possible TCP/UDP port (so thousands in total), without actually using them, what would be the cost in terms of performance?
Is it merely an administrative ...
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How to interpret the refcnt field in /proc/crypto?
Here's an example /proc/crypto entry:
name : md5
driver : md5-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
internal : no
type : shash
...
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rsyslog holds on to dirty pages and does not flush pages to disk
We have kernel dirty bytes settings configured as below.
vm.dirty_background_bytes = 262144000
vm.dirty_background_ratio = 0
vm.dirty_bytes = 0
vm.dirty_expire_centisecs = 0
vm.dirty_ratio = 10
vm....
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How to force Linux to load a custom device tree instead of the built-in DTB?
I'm trying to bring up a WWAN modem on a Dell Latitude 7455 laptop running Linux.
The modem is connected via PCIe domain 0005, but that PCIe controller is currently disabled in the default device tree....
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How to use ≥ 16 usbip ports from one host controller on Debian?
I have 5 USB-over-IP hubs with 16 usb ports, also in future can have some hubs with 64 usb ports, and all should be connected to one virtual machine. But in Debian by default 15 usb port from one host ...
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Are loads and stores to pointers atomic on Linux?
I came across the following quote in this LWN article:
Answer: On all systems running Linux, loads from and stores to pointers are atomic, that is, if a store to a pointer occurs at the same time as ...
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Help needed interpreting stack trace from unexpected watchdog reset
I'm running the Nvidia flavour of Ubuntu 18.04 with kernel 4.9.140 on a TX2i using the official devkit carrier board. The system suffered a watchdog reset. I managed to capture some log output over ...
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Kernel don't recognize my CPU (microcode is not loaded)
I have laptop from 2025 (Lenovo Legion Pro 5 16IAX10 Ultra 7 255HX) and Fedora don't recognize the CPU:
$ sudo dmesg | grep microcode
[ 0.000000] x86/CPU: Model not found in latest microcode list
[ ...
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How does memory.max.swap work in linux's cgroup v2?
I can't figure out how swap limitation should work based on the documentation.
https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html
memory.swap.max
A read-write single value file which ...
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What is the difference between keyctl search and keyctl request?
I am using keyctl to load and retrieve keys for encryption/decryption for an application.
I notice I am able to retrieve the key id of an encrypted key (for example called 'datakey') which has already ...
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How does the Linux kernel decide whether to deny memory allocation or invoke the OOM killer when a cgroup exceeds its memory limit?
This question comes from my curiosity about how Kubernetes handles resource requests and limits, especially memory constraints defined for pods.
I understand that Kubernetes uses cgroups under the ...
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No /dev/sr0 when booting with customized kernel in qemu
I'm compiling a customized kernel for vm without module support. The CONFIG_BLK_DEV_SR is compiled into the kernel, but it /dev/sr0 still not showing up in /dev:
# qemu-system-x86_64 -accel kvm -...
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