parallel memory optimization and -j 0 usage

[Vijish Vijayan]

Hi,

I have been using parallel for some time. I have two queries regarding parallel:

Memory
Does Parallel optimize memory usage or is there any switch to control memory usage.

-j0 and tail -f
Running parallel as:
tail -f jobsqueue | parallel -j0 &

I give a number of input commands to jobsqueue file as required. However, I find no activity going on.

But when the tail process is killed. ( pkill tail ). Parallel starts running all the jobs so far queued to jobsqueue at the same time.

I would like to know if there is a way by which parallel will determine (and execute) the maximum jobs it can execute at a time from a given queue of jobs.

Thanks,
Vijish