Questions tagged [cpu]
The CPU (Central Processing Unit), is the chip in the computer that actually performs the operations and calculations that are done as a program runs. It is essentially what executes a program.
872 questions
0
votes
1
answer
27
views
Kernel message "unchecked MSR access error: RDMSR from ... microcode_loader_disabled..." in Linux 6.6.113 on AMD Geode CPU
I got confused when the dmesg output of an embedded system started with these messages:
[ 0.000000] unchecked MSR access error: RDMSR from 0x8b at rIP: 0xc156f2b0 (microcode_loader_disabled+0x3b/...
- 1,777
3
votes
5
answers
1k
views
Determine which are P-cores/E-cores (Intel CPU)
I have a Intel Core Ultra 5 135U processor with heterogenous cores (performance, power-efficient and low power efficient).
How do I check which processor is which?
I tried to see /proc/cpuinfo, but ...
- 187
2
votes
1
answer
37
views
Probing Hardware for Sensor Data with High Frequency (Temperature and CPU clock frequency)
I'm trying to learn how to probe my CPU sensor data. I need at most 1 to 2 ms sampling period. Using hwmon this could be possible for the temperature data.
But so far I only discovered the CPUfreq ...
- 25
1
vote
1
answer
241
views
How to measure actual CPU utilization in Linux for multi core applications?
I have a computation intensive process that I need to run multiple times on a multi-core processor but "top" isn't showing utilization or load in a useful way.
For example, imagine my task ...
- 113
19
votes
1
answer
2k
views
CPU number not equal to threads per core X cores per socket X sockets
As far as I understand, the number of CPUs in my computer should be given by
CPU = Thread(s) per core x Core(s) per socket x Socket(s)
Here are the first few lines of the lscpu output:
$ lscpu | head -...
- 193
2
votes
1
answer
2k
views
Why does Windows 11 work in Qemu with CPU type qemu64?
I am not sure whether this question is more related to Linux or to Windows. However, here we go:
Using qemu-system-x86_64 7.2.15 on Debian bookworm with kernel 6.1.0 / amd64 on a server with two Xeon ...
- 3,941
1
vote
0
answers
97
views
Alternate way to get the CPU cache size
I have a project where I need to get the size of the cache on my Linux machine. I don't know the linux distro, and the /etc/os-release file does not exist.
I only know the kernel and architecture:
...
- 111
2
votes
1
answer
4k
views
ASUS motherboard fan control under Linux
I built a machine using an ASUS TUF GAMING B650M-PLUS motherboard and a Ryzen 7 8700G CPU. Linux installed with no problems, but I am missing fan control and monitoring.
Under Windows, I use ASUS ...
- 17.4k
2
votes
0
answers
108
views
IRQ Latency and CPU Use
I am running a system with RT-Preempt kernel v6.4.8-rt8
CPU is 12th Gen Intel(R) Core(TM) i7-12800HE
This system is receiving data through the CAN Bus. Every 1 millisecond a burst of 3 messages is ...
- 121
0
votes
0
answers
40
views
Linux kernel cgroup v2 CFS - cpu throttled_usec accounting?
In Linux kernel cgroup v2’s CFS scheduler, how is cpu.stat throttled_usec accounted when a cgroup with multiple threads gets throttled during a single quota period? Specifically, is throttled_usec ...
- 921
0
votes
1
answer
155
views
Why is the Linux CPU stalling when having multithreaded memory writes?
HW Specs:
CPU: 64 Cores, 128 Threads, AMD Ryzen Threadripper Pro 5995WX
RAM: 512 GB, Manufacturer unknown, will try to provide if needed
Linux Specs:
OS: Ubuntu 22.04.4 LTS
Linux Kernel: 5.15.0-...
- 1
0
votes
1
answer
95
views
Linux Fedora suddenly much slower... only on one computer
I have two computers running fully updated Fedora 40. The two computers have the exact same packages installed. They are not identical, but very similar and bought at the same time: Dell Optiplex 7000 ...
- 519
-1
votes
1
answer
42
views
(Solaris) Ram CPU monitoring script is grabbing incorrect cpu ram utilization values
host=$(hostname)
email="[email protected]" # Change to your desired email
subject="Attention!!! Health check Failed on $host"
echo $(date)
# CPU use threshold
cpu_threshold=0
# ...
0
votes
1
answer
1k
views
How to check NPU and if possible disable it? (battery savings purpose)
I have read that recent cpus have NPU (neural processing units) too and i would like to disable this feature if possible because i suspect it is the root cause draining my battery faster than windows.....
- 33
0
votes
1
answer
109
views
Why is Linux in ChromeOS Flex reporting wrong number of CPU sockets?
dajnyx@penguin:~$ lscpu
...
CPU(s): 2
On-line CPU(s) list: 0,1
Vendor ID: GenuineIntel
Model name: Intel(R) Celeron(R) CPU 1037U @ 1.80GHz
CPU ...
- 1
25
votes
2
answers
2k
views
Why are my benchmark times not repeatable, even for a CPU-bound task?
I'm running some benchmarks on my Linux desktop/laptop computer, but I'm not getting reliable results. I'm running a CPU-intensive task that does negligible I/O and doesn't use much RAM. My computer ...
0
votes
1
answer
76
views
slurm - minimizing effect of offline CPUs
I am doing experiments seeing how slurm behaves when it finds offline CPUs. In my experiments, slurm provides configurations that make available too few CPUs. Here's a few examples from an 8-cpu node ...
- 785
5
votes
2
answers
3k
views
irq/9-acpi process using 27% cpu
I see this process constantly using 20+% cpu
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
129 root -51 0 0 0 0 S 27.2 0.0 9,04 [irq/9-acpi]
...
- 81
1
vote
0
answers
445
views
How to isolate cpu cores, even from kernel space, at boot?
I have a faulty Ryzen 5900X desktop CPU. Previously, I somewhat tamed its faulty cores via isolcpus=2,3,14,15 kernel parameter in GRUB2 (see https://blog.cbugk.com/post/ryzen-5850x/).
However, on ...
- 446
1
vote
0
answers
403
views
lm-sensors, CPU sensors not detected
I have a fresh install of Manjaro running on a server i have built. I have an AMD Genoa 9334 ES. On windows I can detect the correct core temperature (see attached images). On the linux OS (Ubuntu 24....
- 11
2
votes
1
answer
216
views
How to disable logical processors in OpenBSD?
It is well known that OpenBSD disables hyper-threading by default. However, htop shows 16 CPUs: 8 online and 8 offline, which takes extra space on the screen and is not very informative.
Moreover, ...
- 441
0
votes
0
answers
219
views
How to disable Processor Performance Boost Mode in PopOS (Or similar distros)
So in Windows 10, I have to edit the registry to make this option available so I can disable it. Why do I need to do this? Because the processor will boost beyond the total power output of my laptop's ...
1
vote
0
answers
112
views
Avoiding the need for reboots when CPU thermally throttles itself
I'm on a Dell laptop with Sandy Bridge Intel(R) Core(TM) i7-2620M CPU @ 2.70GHz CPU
running a 5.15.0-100-generic Linux kernel.
The CPU goes up to 3.4GHz (as both the MATE CPU Frequency Monitor ...
- 29.7k
1
vote
2
answers
6k
views
Using thermald for cpu to stop overheating
Sometimes, my laptop with Intel Core i3 is overheating. For example today.
$ sensors
radeon-pci-0300
Adapter: PCI adapter
temp1: +59.0°C (crit = +120.0°C, hyst = +90.0°C)
coretemp-isa-0000
...
- 15.3k
1
vote
1
answer
118
views
Curious lscpu Output Related to CPU Calculation
I have been trying to understand lscpu's output and came across several threads dedicated to concepts of CPUs, physical cores, and threads. Based on those threads, to get the total number of CPUs (...
- 13