Re: [dpdk-dev] [PATCH 3/4] eal: allow checking CPU flags by name

[David Marchand <david.marchand@redhat.com>]

On Fri, Jun 28, 2019 at 2:40 PM Bruce Richardson <bruce.richardson@intel.com>
wrote:

> On Thu, Jun 27, 2019 at 03:22:14PM +0200, David Marchand wrote:
> >    On Wed, May 29, 2019 at 5:42 PM Bruce Richardson
> >    <[1]bruce.richardson@intel.com> wrote:
> >
> >      Rather than using enum values for CPU flags, which means the symbols
> >      don't
> >      exist on other architectures, provide a flag lookup by name,
> >      allowing us to
> >      unconditionally check for a CPU flag.
> >
> >    Did you consider passing a string for the CPU architecture rather than
> >    an enum?
> >    It would have to be compared to RTE_ARCH in
> >    rte_cpu_get_flagname_enabled.
> >    Or to accomodate with x86_64/i686, this could be a cpu arch family.
> >    This avoids adding a new C type that seems quite limited wrt its uses.
> >    --
> >    David Marchand
> >
>
> I'm not sure I really see the value in having string names for the
> architecture values, I think it would be a lot more clunky to manage rather
> than having an enum value. The key difference vs the flags is that the
> flags are only valid per-architecture while the architecture defines can be
> globally valid, and secondly there is a finite, and small, number of
> architectures compared to the number of flags supported.
>
> If you feel strongly about it I can investigate it, but I'm not sure I see
> the value in doing so right now if the only benefit is avoiding the enum.
>

I suppose we won't have too much trouble handling ABI breakage (thinking
about when we will remove x86 support).
Ok, let's go with this.


-- 
David Marchand