Linux – How to Limit Network Bandwidth

Have a look at trickle a userspace bandwidth shaper. Just start your shell with trickle and specify the speed, e.g.:

trickle -d 100 zsh

which tries to limit the download speed to 100KB/s for all programs launched inside this shell.

As trickle uses LD_PRELOAD this won't work with static linked programs but this isn't a problem for most programs.

Wanted to post the answer to this question in case anyone else sees a similar confusing result. It looks like I had two problems:

• Need to use # of cpus on host, not # available CPUs in the cgroups cpuset to estimate CPU bandwidth:

  (# of cpus on the host) * (cpu.cfs_period_us) * (.25) so 40 * 100000 * .25 = 1000000

• My run of stress-ng inside the container was using the cpu and cpuset controllers of the /lxc/foo cgroup while the run of stress-ng outside of the container was using the /system/sshd.service cgroup

To better model my real world application I should have specified which controllers to use by using cgexec:

$ cgexec -g cpuset:/lxc/foo -g cpu:/lxc/foo ./stress-ng --cpu-load 100 -c 48 --times --timeout 10s --metrics-brief  
stress-ng: info: [6252] dispatching hogs: 48 cpu  
stress-ng: info: [6252] successful run completed in 10.36s  
stress-ng: info: [6252] stressor      bogo ops real time  usr time  sys time   bogo ops/s   bogo ops/s  
stress-ng: info: [6252]                          (secs)    (secs)    (secs)   (real time) (usr+sys time)  
stress-ng: info: [6252] cpu              11152     10.09    102.83      0.12      1105.60       108.32  
stress-ng: info: [6252] for a 10.36s run time:  
stress-ng: info: [6252]     414.46s available CPU time  
stress-ng: info: [6252]     102.85s user time   ( 24.82%)  
stress-ng: info: [6252]       0.12s system time (  0.03%)  
stress-ng: info: [6252]     102.97s total time  ( 24.84%)