Re: [dpdk-dev] [PATCH 07/10] eal: add core list input format

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

> > > > Do you want to burn an option letter on that?  It seems like it
> > > > might be better to search the string for 0x and base the selection
> > > > of bitmap of list parsing based on its presence or absence.
> >
> > It was the initial proposal (in April):
> > 	http://dpdk.org/ml/archives/dev/2014-April/002173.html
> > And I liked keeping only 1 option;
> > 	http://dpdk.org/ml/archives/dev/2014-May/002722.html
> > But Anatoly raised the compatibility problem:
> > 	http://dpdk.org/ml/archives/dev/2014-May/002723.html
> > Then there was no other comment so Didier and I reworked a separate
> option.
> >
> > > The existing coremask parsing always assumes a hex coremask, so just
> > > looking for a 0x will not work. I prefer this scheme of using a new
> > > flag for this method of specifying the cores to use.
> > >
> > > If you don't want to use up a single-letter option, two alternatives:
> > > 1) use a long option instead.
> > > 2) if the -c parameter includes a "-" or a ",", treat it as a
> > > new-style option, otherwise treat as old. The only abiguity here
> > > would be for specifying a single core value 1-9 e.g. is "-c 6" a mask with
> two bits, or a single-core to run on.
> > > [0 is obviously a named core as it's an invalid mask, and A-F are
> > > obviously masks.] If we did want this scheme, I would suggest that
> > > we allow trailing commas in the list specifier, so we can force
> > > users to clear ambiguity by either writing "0x6" or "6," i.e. disallow
> ambiguous values to avoid problems.
> > > However, this is probably more work that it's worth to avoid using
> > > up a letter option.
> > >
> > > I'd prefer any of these options to breaking backward compatibility in this
> case.
> >
> > We need a consensus here.
> > Who is supporting a "burn" of an one-letter option with clear usage?
> > Who is supporting a "re-merge" of the 2 syntaxes with more complicated
> > rules (list syntax is triggered by presence of "-" or ",")?
> >
> 
> Burn!

I would still prefer a long option (we already have a coremask parameter, so another one is kind-of non-essential and IMO shouldn't belong in a scarce resource of one-letter parameters), but if everyone else agrees, the "burn" option is much more preferable to me than complicating syntax of an already existing parameter.

Thanks,
Anatoly