Re: [PATCH 0/7] Patches to split architecture specific operations from DPDK

[Bruce Richardson <bruce.richardson-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

On Fri, Oct 03, 2014 at 03:21:53PM +0200, David Marchand wrote:
> Hello Chao,
> 
> On Fri, Sep 26, 2014 at 11:33 AM, Chao Zhu <bjzhuc-vtt25B2cwJLQT0dZR+AlfA@public.gmane.org> wrote:
> 
> > The set of patches split x86 architecture specific operations from DPDK
> > and put them to the
> > arch directories of i686 and x86_64 architecture. This will make the
> > adpotion of DPDK much easier
> > on other computer architecture. For a new architecture, just add an
> > architecture specific
> > directory and necessary building configuration files, then DPDK can
> > support it.
> >
> >
> Here is a different approach for the headers splitting.
> 
> If we are going to support multiple architectures, the best would be to
> have a specific header for each arch which implements a common API (no need
> for any _arch suffix).
> These headers would be located in lib/librte_eal/common/include/arch/$arch/
> rather than lib/librte_eal/common/include/$arch/arch/ (which looks odd to
> me).
> Makefiles can add some -I for dpdk to build itself (and we can remove those
> symlinks from the makefiles).
> Makefiles only install the specific headers in RTE_SDK/include for use by
> applications.
> 
> For common code and documentation, we can add a "generic" directory in
> lib/librte_eal/common/include (or "arch-generic", or "shared" ... any
> better idea ?).
> DPDK makefiles installs the generic headers in RTE_SDK/include/generic.
> arch headers (like rte_atomic.h) include the generic one
> (<generic/rte_atomic.h>).
> 
> These generic headers can be implemented using compiler intrinsics when
> possible.
> They also include the doxygen stuff in a single place.
> 
> 
> This would look like something like this, for rte_atomic.h :
> - in DPDK sources
> $ ls lib/librte_eal/common/include/*/rte_atomic.h
> lib/librte_eal/common/include/i686/rte_atomic.h
> lib/librte_eal/common/include/x86_64/rte_atomic.h
> lib/librte_eal/common/include/generic/rte_atomic.h
> 
> - in installed RTE_SDK
> $ ls RTE_SDK/include/{,*/}rte_atomic.h
> RTE_SDK/include/rte_atomic.h
> RTE_SDK/include/generic/rte_atomic.h
> 
> Comments ?
> 
> 
> I am only focusing on the first patchset at the moment, but if we can find
> consensus here, a respin of the two patchsets would be great.
> 
> Thanks.
> 
> -- 
> David Marchand


I would have no objection to such a scheme. However, I'm not seeing much 
advantage over the existing way of doing things. I think I'd rather see the 
proposed patch sets merged first and then any additional cleanup done, 
rather than holding up a worthwhile submission for a bit of tidy-up.

/Bruce