Re: [dpdk-stable] [PATCH] net/bnxt: allow configuring vector mode

[Ajit Khaparde <ajit.khaparde@broadcom.com>]

On Tue, Mar 31, 2020 at 4:36 AM Ferruh Yigit <ferruh.yigit@intel.com> wrote:

> On 3/5/2020 10:18 PM, Stephen Hemminger wrote:
> > On Thu, 5 Mar 2020 15:10:48 -0500
> > Lance Richardson <lance.richardson@broadcom.com> wrote:
> >
> >> Hi Stephen,
> >>
> >> On Thu, Mar 5, 2020 at 1:45 AM Stephen Hemminger
> >> <stephen@networkplumber.org> wrote:
> >>>
> >> <snip>
> >>>
> >>> Make the configuration use the same as other drivers with
> >>> vector mode: ixge, i40e, ...
> >> s/ixge/ixgbe/?
> >>
> >>>
> >> <snip>
> >>> This will also make future support of vector mode on other
> >>> architectures possible.
> >>>
> >>> Fixes: bc4a000f2f53 ("net/bnxt: implement SSE vector mode")
> >> <snip>
> >>> +#error "bnxt: IEEE1588 is incompatiable with vector mode"
> >>> +#endif
> >> s/incompatiable/incompatible/
> >>
> >>
> >> This was this approach taken in the initial patch set to add bnxt
> >> vector mode support,
> >> however based on feedback the current approach was used instead. That
> discussion
> >> can be found here:
> >>       http://patches.dpdk.org/patch/53683/
> >>
> >> If mark support could be treated as a receive offload, it would be
> >> possible to choose
> >> the non-vector receive handler based on whether mark is enabled. Adding
> a kvargs
> >> option to disable vector mode might be another possibility. Otherwise,
> >> a build-time
> >> configuration option does seem to be useful.
> >>
> >> LGTM... with the above:
> >>
> >> Acked-by: Lance Richardson <lance.richardson@broadcom.com>
> >
> > What ever solution must be consistent across all drivers.
> >
>
> I saw Ajit merged this patch to brcm tree, but I am not sure about it. We
> have
> already removed this compile time option from some PMDs, and driver tries
> to
> detect to use or not to use vectorization transparently.
>
> This config is also a problem for the meson, which always sets the flag in
> a
> hardcoded way.
>
> But also I am not sure about to need to enable/disable vectorization
> explicitly,
> this patch seems because of this need. As far as I remember in the past
> this
> type of runtime configuration rejected to not make driver configuration
> more
> complex.

Since we need a way to disable or enable vector mode.
May be a dev parameter could be used?
That way it would not interfere with the meson builds and also allow a
user/application to set vector mode setting as desired.