sylabs/singularity-userdocs

--cpus option units

dmd opened this issue · 1 comments

dmd commented

According to https://docs.sylabs.io/guides/main/user-guide/cgroups.html :

--cpus sets the number of CPUs, or fractional CPUs, that the container can use. The minimum is 0.01 or one tenth of a physical CPU. The maximum is the number of CPU cores on your system.

What are the units here? 0.01 seems to me like it's one hundredth of a physical CPU, not one tenth.

Thanks, we'll fix this. Hundredths is correct. The unit is a CPU (16 on this machine and the code knows the correct valid range if you try e.g. 0.009).

05:59 pm $ singularity run --cpus 0.01 docker://alpine
INFO:    Using cached SIF image
Singularity> ^C

Singularity> 
dtrudg-sylabs@mini:~/Git_Sylabs/singularity
06:00 pm $ singularity run --cpus 0.009 docker://alpine
INFO:    Using cached SIF image
FATAL:   cpus value must be in range 0.01 - 16