Re: Parallel launches each command j times

[conahorse]

Il giorno 27/gen/2015, alle ore 23:42, Ole Tange <ole@tange.dk> ha scritto:

> On Sun, Jan 25, 2015 at 3:58 PM, conahorse <conahorse@gmail.com> wrote:
> 
>> Hi everyone,
>> I'd like to have parallel lunch
> 
> I like the idea of parallel lunch, mmmm food :-)
> 

xD you could be right on this one, serendipity!

>> at most N commands in parallel on my machine.
>> I have a file where each line corresponds to a command, named
>> commands.exp.
>> What I do is simply this:
>> 
>> paralle -j N < commands.exp
>> 
>> (where N is 8, but nevermind)
>> but I have is that on my netbook I seem to have the first 8 lines running in
>> parallel, but on my other machine (having the same version of parallel and
>> os, namely ubuntu 14.04 parallel@gnu.org), the first 8 lines get 8 processes
>> each! Thus creating a huge bottleneck.
>> What am I missing here? Why does parallel consider each line to be launched
>> 8 times?
> 
> Sounds like a bug. Follow
> http://www.gnu.org/software/parallel/man.html#REPORTING-BUGS and file
> a bug report.
> 

Checking things better it seems like I was wrong in making parallel the 
responsible: running just one of those commands on those machines (without 
parallel) yields the same result, making 8 threads (not processes). I suspect 
this is due to some other interaction like a library, but I cannot recognize 
which one (how could I debug this?), I am simply using python and ipython with 
some line arguments.
I know that this is not the place to talk about this anymore, so I apologize : )

Thanks again

> 
> /Ole