Re: [dpdk-dev] [PATCH RFC 00/13] Update build system

["Gonzalez Monroy, Sergio" <sergio.gonzalez.monroy@intel.com>]

> From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com]
> Sent: Thursday, January 22, 2015 10:39 AM
> To: Gonzalez Monroy, Sergio
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH RFC 00/13] Update build system
> 
> 2015-01-22 10:03, Gonzalez Monroy, Sergio:
> > > From: Gonzalez Monroy, Sergio
> > > Sent: Monday, January 12, 2015 5:22 PM
> > > To: Thomas Monjalon
> > > Subject: Re: [dpdk-dev] [PATCH RFC 00/13] Update build system
> > >
> > > Hi Thomas,
> > >
> > > > From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com]
> > > > Sent: Monday, January 12, 2015 4:52 PM
> > > >
> > > > Hi Sergio,
> > > >
> > > > 2015-01-12 16:33, Sergio Gonzalez Monroy:
> > > > > This patch series updates the DPDK build system.
> > > >
> > > > Thanks for proposing such rework.
> > > > We need discussions on that topic. So I ask some questions below.
> > > >
> > > > > Following are the goals it tries to accomplish:
> > > > >  - Create a library containing core DPDK libraries (librte_eal,
> > > > >    librte_malloc, librte_mempool, librte_mbuf and librte_ring).
> > > > >    The idea of core libraries is to group those libraries that are
> > > > >    always required for any DPDK application.
> > > >
> > > > How is it better? Is it only to reduce dependencies lines?
> > > >
> > > In my opinion I think that there are a set of libraries that are
> > > always required and therefore should be grouped as a single one.
> > > Basically all apps and other DPDK libs would have dependencies to
> > > these core libraries.
> > >
> > > Aside from that, I don't think there is any difference. Note that
> > > this affects shared libraries, with no difference for apps linked against
> static libs.
> > >
> > > > >  - Remove config option to build a combined library.
> > > >
> > > > Why removing combined library? Is there people finding it helpful?
> > > >
> > > I don't think it makes sense from a shared library point of view,
> > > maybe it does for static?
> > > For example, in the case of shared libraries I think we want to try
> > > to avoid the case where we have an app linked against
> > > librte_dpdk.so, but such library may contain different libraries
> > > depending on the options that were enabled when the lib was built.
> > >
> > > The core libraries would be that set of libraries that are always
> > > required for an app, and its content would be fixed regardless of
> > > the option libraries (like acl, hash, distributor, etc.) We could
> > > add more libraries as core if we think it is a better solution, but
> > > the goal should be that librte_core.so contains the same libraries/API
> regardless of the system/arch.
> > >
> > > > >  - For shared libraries, explicitly link against dependant
> > > > >    libraries (adding entries to DT_NEEDED).
> > > >
> > > > OK, good.
> > > >
> > > > >  - Update app linking flags against static/shared DPDK libs.
> > > > >
> > > > > Note that this patch turns up being quite big because of moving
> > > > > lib directories to a new subdirectory.
> > > > > I have ommited the actual diff from the patch doing the move of
> > > > > librte_eal as it is quite big (6MB). Probably a different
> > > > > approach is
> > > > preferred.
> > > >
> > > > Why do you think moving directories is needed?
> > > >
> > > Actually I am not sure is the best way to do this :) There is no
> > > need to move them, as the same result could be achieved without
> > > moving directories, but I thought that it would be easier for anyone to
> see which libraries are 'core'
> > > and which are not.
> > >
> > > Not moving those directories would definitely simplify this patch series.
> > >
> > > > Thanks
> > > > --
> > > > Thomas
> > >
> > > Thanks,
> > > Sergio
> >
> > Hi Thomas,
> >
> > Any other comments/suggestions ?
> > My main concern would be the patch needed to move librte_eal (around
> 6MB).
> >
> > Thoughts?
> 
> I think you shouldn't move the libs.
> Maybe we can link the core libs into one (not sure of the interest) but I think
> we shouldn't move them in a core/ subdir.
> 
> On another side, I'd like to see KNI moving out of EAL.
> 
> --
> Thomas

I think moving KNI out of EAL belongs to a different patch.

We can still link librte_core without moving the directories into core/

I'll work on it.

Thanks,
Sergio