Re: GNU Parallel Bug Reports Use of uninitialized value $swap_out in pattern match

[Ole Tange]

On Wed, Oct 24, 2012 at 3:55 PM, Rhys Ulerich <address@hidden> wrote:
>>> I'm seeing warnings like
>>>
>>>     Use of uninitialized value $swap_out in pattern match (m//) at
>>> /h2/rhys/bin/parallel line 2313.
>>>
>>> on a command like
>>>
>>>     ls | parallel echo {}
>
>> Line 2313 should never be run with the above command.
>>
>> Do you have a profile (~/.parallel/config /etc/parallel/config
>> $PARALLEL) that you run with?
>
> I do.  Sorry to have forgotten to include it:
>
> # As many processes as cores
> -j+0
> # Nice the jobs
> --nice=10
> # Do not start jobs when the system is swapping
> --noswap
>
> Temporarily removing my ~/.parallel/config and re-running 'ls |
> parallel echo' fixes the issue.
>
> With no ~/.parallel/config, running 'ls | parallel --noswap echo'
> exhibits the issue.  --noswap is the culprit.
>
>> Can you reproduce this on other systems?
>
> I've not been able to, no.
>
> What information can I gather about this particular system that might help?

The swap activity is determined from the output of:  vmstat 1 2 - specifically:

{ vmstat 1 2 2> /dev/null || vm_stat 1; } | awk 'NR!=4{next}
NF==16{print $7*$8} NF==11{print $10*$11} {exit}'

What does this output on your system?

/Ole