Re: [PATCH] build: add drivers_install_subdir meson option

[Luca Boccassi <bluca@debian.org>]

On Tue, 2018-10-02 at 13:23 +0100, Bruce Richardson wrote:
> On Tue, Oct 02, 2018 at 01:02:26PM +0200, Marco Varlese wrote:
> > On Mon, 2018-10-01 at 12:24 +0100, Luca Boccassi wrote:
> > > On Mon, 2018-10-01 at 12:06 +0100, Bruce Richardson wrote:
> > > > On Mon, Oct 01, 2018 at 12:42:09PM +0200, Timothy Redaelli
> > > > wrote:
> > > > > On Mon, 01 Oct 2018 10:46:02 +0100
> > > > > Luca Boccassi <bluca@debian.org> wrote:
> > > > > 
> > > > > > On Mon, 2018-10-01 at 10:25 +0100, Bruce Richardson wrote:
> > > > > > > On Mon, Oct 01, 2018 at 10:17:14AM +0100, Bruce
> > > > > > > Richardson
> > > > > > > wrote:  
> > > > > > > > On Fri, Sep 28, 2018 at 06:58:03PM +0100, Luca Boccassi
> > > > > > > > wrote:  
> > > > > > > > > Allow users and packagers to override the default
> > > > > > > > > dpdk/drivers
> > > > > > > > > subdirectory where the PMDs get installed under $lib.
> > > > > > > > > 
> > > > > > > > > Signed-off-by: Luca Boccassi <bluca@debian.org>
> > > > > > > > > ---  
> > > > > > > > 
> > > > > > > > I'm ok with this change, but what is the current
> > > > > > > > location
> > > > > > > > used by
> > > > > > > > distro's
> > > > > > > > right now? I mistakenly never checked what was done
> > > > > > > > before I
> > > > > > > > used
> > > > > > > > dpdk/drivers as a default value, and I'd like the
> > > > > > > > default to
> > > > > > > > match
> > > > > > > > the
> > > > > > > > common option if possible.
> > > > > > > > 
> > > > > > > > /Bruce
> > > > > > > >   
> > > > > > > 
> > > > > > > Replying to my own question, I've just checked on CentOS
> > > > > > > and
> > > > > > > Debian,
> > > > > > > and it
> > > > > > > appears both are using directory "dpdk-pmds" as the
> > > > > > > subdir
> > > > > > > name.
> > > > > > > Therefore,
> > > > > > > let's just make that the default. [Does it need to be
> > > > > > > configurable in
> > > > > > > that
> > > > > > > case?]
> > > > > > > 
> > > > > > > /Bruce  
> > > > > > 
> > > > > > If the default is the one I expect then I'm fine without
> > > > > > having
> > > > > > an
> > > > > > option (actually happier - less things to configure).
> > > > > > 
> > > > > > But in Debian/Ubuntu it's dpdk-MAJORVER-drivers since last
> > > > > > January :-)
> > > > > > We changed because using a single directory creates
> > > > > > problems when
> > > > > > multiple different ABI versions are installed, due to the
> > > > > > EAL
> > > > > > autoload
> > > > > > from that directory. So we need a different subdirectory
> > > > > > per ABI
> > > > > > revision.
> > > > > > 
> > > > > > We were actually talking with Timothy a while ago to make
> > > > > > this
> > > > > > consistent across our distros, and perhaps Marco can chip
> > > > > > in as
> > > > > > well.
> > > > > > 
> > > > > > Timothy, Marco, is using dpdk-MAJORVER-$something ok for
> > > > > > you? I'm
> > > > > > not
> > > > > > too fussy on $something, it can be drivers or pmds or
> > > > > > something
> > > > > > else.
> > > > > > 
> > > > > 
> > > > > LGTM.
> > > > > If needed, we can just do a compatibility symlink using the
> > > > > current
> > > > > dpdk-pmds path
> > > > > 
> > > > 
> > > > One suggestion/comment. Would using a unique directory per
> > > > release
> > > > not lead
> > > > to clobbering up the lib directory unnecessarily? How about
> > > > having a
> > > > single
> > > > "dpdk" or "dpdk-pmds" directory in lib, and having $MAJORVER as
> > > > a
> > > > subdir
> > > > under that?
> > > > 
> > > > E.g. dpdk/pmds-18.08/, dpdk/pmds-18.11/, or dpdk-pmds/18.08/
> > > > dpdk-pmds/18.11
> > > > 
> > > > [The former of the above would be my preference, since I don't
> > > > like
> > > > having
> > > > hypenated names, and like having "dpdk" alone as a folder name
> > > > :-)]
> > > > 
> > > > /Bruce
> > > 
> > > dpdk/pmds-XX.YY/ would work for me. Timothy and Marco?
> > 
> > That would work for us.
> > However, I would suggest to have the path to be configurable
> > (feature to be
> > dropped in maybe next release). Just to make sure the transition
> > can happen
> > without pain in the remote circumstance that something goes wrong
> > with
> > packaging...
> > > 
> > 
> > -- 
> > Marco V
> > 
> 
> Yes, I think it needs to be configurable for the forseeable future.
> If the
> DPDK version is to be put in the path then we either need to always
> use a
> configurable version, since we can't hardcode a version number in the
> default, or else we need to put logic in the meson.build file to
> always
> insert a version number.
> 
> /Bruce

Ok, in v2 I added a small bit of logic to set the default to the major
version number (and also the override option).

-- 
Kind regards,
Luca Boccassi