Questions tagged [cgroups]
Linux cgroups (control groups) allow limiting and accounting for resources on a system, including CPU, memory, and block I/O.
357 questions
1 vote
1 answer
38 views
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....
- 11
14 votes
1 answer
1k views
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 ...
- 143
2 votes
0 answers
82 views
cgroup / cpu scheduler tuning questions, cpu pressure & uclamp behavior
I've been working on this for a few days and I'm scratching my head. The kernel docs for cgroups, pressure stall information, and the scheduler have not helped me shed any light on this so far, so I ...
- 21
1 vote
0 answers
97 views
Too slow Tiered Memory Demotion and CPU Lock-up(maybe) with cgroup v2 memory.high
We are currently testing tiered memory demotion on a machine equipped with a CXL device. To facilitate this, we created a specific script (https://github.com/hyun-sa/comem) and are using the memory....
- 11
0 votes
0 answers
63 views
cgoups: how safe is changing cpuset of a process?
I've recently started to observe unexpected output (and later stty -a outputs terminal settings different from new shell tab) from my shell scripts project. As of now, I'm very close to be sure the ...
- 1,319
1 vote
1 answer
227 views
Cgroups permission denied on Ubuntu 22.04.5 but works on Ubuntu 22.04.03
I'm trying to learn about cgroups. I ran these two commands: root@localhost:~# mkdir /sys/fs/cgroup/container_cpu root@localhost:~# echo '50000 100000' | sudo tee /sys/fs/cgroup/container_cpu/cpu.max ...
- 631
1 vote
1 answer
269 views
isolcpus kernel option appears to break taskset
I have a laptop with an Intel Core i7-12700H CPU, running Ubuntu 24.04 LTS. This CPU has 6 “performance“ cores, each one running 2 threads, and 8 “efficient” cores. Most of the time, the “efficient” ...
- 1,729
1 vote
1 answer
61 views
Performance Degradation with rsync in container or cgroupv2 with MEM limit
I'm experiencing a significant performance degradation when using "rsync" to copy files over the network from within a container or cgroup with memory limits on Oracle Linux 9.2. The issue ...
- 921