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Subject: Re: [OMPI devel] RFC: Drop all mpirun single-dash multi-letter CLI options (except -np)
From: Ralph Castain (rhc_at_[hidden])
Date: 2014-01-07 18:17:11


+1

On Jan 7, 2014, at 1:49 PM, Jeff Squyres (jsquyres) <jsquyres_at_[hidden]> wrote:

> WHAT: Drop mpirun single-dash CLI options such as -bynode (but keep the double-dash equivalents, like --bynode)
>
> WHY: It's a well-established de facto CLI option standard:
> "-" is used for single-letter options
> "--" is used for tokenized options
>
> WHERE: probably mostly in orte/tools/orterun
>
> WHEN: 1.9
>
> TIMEOUT: Teleconf, Tuesday 21 Jan 2014
>
> MORE DETAIL:
>
> We've supported single- and double-dash variants of many mpirun options for several years (e.g., --bynode and -bynode). With the exception of "-np", there's really no reason we should support the single-dash versions ("-np" is pretty universally expected in the MPI/HPC world; I don't think we'll ever be able to get rid of it).
>
> Let's deprecate all single-dash options (except -np) in 1.7.5/1.8 and eliminate them in 1.9. Specifically, let's do something like this in 1.7.5:
>
> -----
> $ shell mpirun -bynode -np 4 a.out
> ------------------------------------------------------------------------
> You used the "-bynode" option to mpirun, which, although it still functions
> as you would expect it to, is now deprecated. The exactly-equivalent "--bynode"
> option replaces the "-bynode" option.
>
> *** NOTE THAT -bynode OPTION WILL DISAPPEAR IN A FUTURE VERSION OF OPEN MPI! ***
>
> To be compatible with future versions of Open MPI, use the "--bynode" option.
>
> If you can't easily change your mpirun command line, then you can set the MCA
> parameter orterun_i_promise_to_update_my_cli_options_before_ompi_1_9 to 1,
> which will suppress this message.
> ------------------------------------------------------------------------
> -----
>
> This gives the user two clear options:
>
> 1. Update from -foo to --foo to be forward compatible
> 2. Set an MCA parameter to suppress the message, but risk not being forward compatible
>
> Then, on trunk/v1.9, we remove all the single-dash options.
>
> Comments?
>
> --
> Jeff Squyres
> jsquyres_at_[hidden]
> For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
>
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