~/container/cpu-shares$ bash cpu-shares-bug.sh
Note: JavaStress.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
Sending build context to Docker daemon  46.08kB
Step 1/4 : FROM docker.io/library/openjdk:17-jdk-slim
 ---> 2a9873d16f48
Step 2/4 : COPY stress /bin
 ---> Using cache
 ---> 4fff027afda4
Step 3/4 : COPY JavaStress*.class /
 ---> 16807a6cb508
Step 4/4 : CMD ["bash"]
 ---> Running in c0fc5ac68617
Removing intermediate container c0fc5ac68617
 ---> 58146bd9c232
Successfully built 58146bd9c232
Successfully tagged my-openjdk17-image:latest
This machine has 32 cpus
#----------------------------------------------------------------------
# (1) See how much CPU we can get from the stress command with two
#     containers, each with --cpu-shares=100
# baseline: run a single container without --cpu-shares
stress: info: [8] dispatching hogs: 32 cpu, 0 io, 0 vm, 0 hdd
stress: info: [8] successful run completed in 10s

real	0m10.005s
user	5m17.440s
sys	0m0.077s
----------------------------------------
+ cat stress.1.log
stress: info: [8] dispatching hogs: 32 cpu, 0 io, 0 vm, 0 hdd
stress: info: [8] successful run completed in 10s

real	0m10.005s
user	2m0.906s
sys	0m0.019s
----------------------------------------
+ cat stress.2.log
stress: info: [8] dispatching hogs: 32 cpu, 0 io, 0 vm, 0 hdd
stress: info: [8] successful run completed in 10s

real	0m10.008s
user	3m19.141s
sys	0m0.057s
#----------------------------------------------------------------------
# (2) See how much CPU we can get from with the JavaStress program with two
#     containers, each with --cpu-shares=100
# baseline: run a single container without --cpu-shares
Runtime.getRuntime().availableProcessors() = 32
ForkJoinPool.commonPool().getParallelism() = 31
Elapsed = 10001 ms, counter = 280710

real	0m10.257s
user	5m7.419s
sys	0m3.891s
----------------------------------------
+ cat JavaStress.1.log
Runtime.getRuntime().availableProcessors() = 1
ForkJoinPool.commonPool().getParallelism() = 1
Elapsed = 10000 ms, counter = 29208

real	0m10.154s
user	0m22.193s
sys	0m0.501s
----------------------------------------
+ cat JavaStress.2.log
Runtime.getRuntime().availableProcessors() = 1
ForkJoinPool.commonPool().getParallelism() = 1
Elapsed = 10000 ms, counter = 32792

real	0m10.150s
user	0m22.438s
sys	0m0.340s