Re: [dpdk-dev] [PATCH 1/1] build: allow disabling libs

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

On Thu, Jun 15, 2023 at 10:43 AM Bruce Richardson
<bruce.richardson@intel.com> wrote:
>
> On Wed, Jun 14, 2023 at 12:09:51PM -0700, Stephen Hemminger wrote:
> > On Fri, 18 Sep 2020 14:57:50 +0100
> > Bruce Richardson <bruce.richardson@intel.com> wrote:
> >
> > > On Fri, Sep 18, 2020 at 02:54:21PM +0200, Mohammed Hawari wrote:
> > > > Hello Bruce,
> > > >
> > > > Thanks for the quick response, see inline
> > > >
> > > > Best regards,
> > > >
> > > > Mohammed
> > > >
> > > > > On 18 Sep 2020, at 13:43, Bruce Richardson <bruce.richardson@intel.com> wrote:
> > > > >
> > > > > On Fri, Sep 18, 2020 at 10:49:23AM +0200, Mohammed Hawari wrote:
> > > > >> Similarly to the disable_drivers option, the disable_libs option is
> > > > >> introduced. This allows to selectively disable the build of elements
> > > > >> in libs to speed-up the build process.
> > > > >>
> > > > >> Signed-off-by: Mohammed Hawari <mohammed@hawari.fr>
> > > > >> ---
> > > > >
> > > > > While I don't particularly like allowing libs to be enabled and disabled
> > > > > since it complicates the build, I can see why it's necessary. This is an
> > > > > area that does need some discussion, as I believe others have some opinions
> > > > > in this area too.
> > > > >
> > > > > However, for now, some additional thoughts, both on this patch and in
> > > > > general:
> > > > >
> > > > > 1. I see you included disabling apps if their required libs are not
> > > > >   available. What about the drivers though?
> > > > To my understanding, in the current code, the drivers/meson.build file already
> > > > does that check with:
> > > >
> > > > foreach d:deps
> > > >                 if not is_variable('shared_rte_' + d)
> > > >                     build = false
> > > >
> > >
> > > Yes, my mistake, I forgot that that was added as one driver could depend
> > > upon another. :-(
> > >
> > > > > 2. A bigger issue is whether this is really what we want to do, guarantee a
> > > > >   passing build even if vast chunks of DPDK are actually enabled? I'd tend
> > > > >   towards "no" in this case, and I'd rather see disabling of libs more
> > > > >   constrained.
> > > > > 3. To this end, I think I'd rather see us maintain a set of libs which are
> > > > >   allowed to be disabled, and prevent the rest from being so. For example,
> > > > >   it makes no sense in DPDK to disable the EAL or mempool libs, since nothing
> > > > >   will build, while the bitrate_stats or latency_stats libs could likely
> > > > >   be disabled with little or no impact.
> > > > I tend to agree with that more structured approach, but I am going to wait until
> > > > we get some more thoughts from the community before starting that work.
> > > >
> > >
> > > That seems a wise approach. If there is no consensus after a while here, it
> > > probably needs to go to the technical board.
> >
> >
> > Marking current patch as "Changes requested".
> > Assume that if someone wants to go further then and propose a more
> > targeted build setting. Something like minimal??
>
> The more targetted approach has been implemented and can constantly be
> improved upon. We can already disable a set of libraries, with only those
> validated as being ok to disable on that list. Therefore, I think this
> patch can just be rejected as obsolete. Any additional work in this area
> should be:
> * increasing list of optional libs
> * looking again at adding an "enable_libs" flag. I was against this
>   previously, but now think it's time may have come!

I still have my patch on enable_libs that I rebased not too long ago
(around the time the iova va build option was touched by Thomas).
I could retest it and post it if it helps.



-- 
David Marchand