[dpdk-dev] [PATCH v2 1/4] mk: Remove combined library and related options

[Neil Horman]

On Fri, Mar 13, 2015 at 11:48:59AM +0000, Gonzalez Monroy, Sergio wrote:
> On 13/03/2015 11:34, Kavanagh, Mark B wrote:
> >>On 13/03/2015 10:49, Kavanagh, Mark B wrote:
> >>>>---
> >>>>config/common_bsdapp                        |   6 --
> >>>>config/common_linuxapp                      |   6 --
> >>>>config/defconfig_ppc_64-power8-linuxapp-gcc |   2 -
> >>>>lib/Makefile                                |   1 -
> >>>>mk/rte.app.mk                               |  12 ----
> >>>>mk/rte.lib.mk                               |  35 ----------
> >>>>mk/rte.sdkbuild.mk                          |   3 -
> >>>>mk/rte.sharelib.mk                          | 101 ----------------------------
> >>>>mk/rte.vars.mk                              |   9 ---
> >>>>9 files changed, 175 deletions(-)
> >>>>delete mode 100644 mk/rte.sharelib.mk
> >>>>
> >>>>diff --git a/config/common_bsdapp b/config/common_bsdapp
> >>>>index 8ff4dc2..7ee5ecf 100644
> >>>>--- a/config/common_bsdapp
> >>>>+++ b/config/common_bsdapp
> >>>>@@ -79,12 +79,6 @@ CONFIG_RTE_FORCE_INTRINSICS=n
> >>>>CONFIG_RTE_BUILD_SHARED_LIB=n
> >>>>
> >>>>#
> >>>>-# Combine to one single library
> >>>>-#
> >>>>-CONFIG_RTE_BUILD_COMBINE_LIBS=n
> >>>>-CONFIG_RTE_LIBNAME=intel_dpdk
> >>>Hi Sergio,
> >>>
> >>>Removing these options breaks compatibility with OVS. While it may be feasible to link
> >>to individual static libraries, in our experience, a single combined library provides a
> >>much more convenient way of linking.
> >>>Thanks,
> >>>Mark
> >>>
> >>>>-
> >
> >(snip)
> >
> >
> >>>>-endif
> >>>>-
> >>>>-RTE_LIBNAME := $(CONFIG_RTE_LIBNAME:"%"=%)
> >>>>-ifeq ($(RTE_LIBNAME),)
> >>>>-RTE_LIBNAME := intel_dpdk
> >>>>endif
> >>>>
> >>>># RTE_TARGET is deducted from config when we are building the SDK.
> >>>>--
> >>>>1.9.3
> >>Hi Mark,
> >>
> >>How does this patch break compatibility with OVS?
> >>
> >>Thanks,
> >>Sergio
> >Hey Sergio,
> >
> >We use the CONFIG_RTE_BUILD_COMBINE_LIBS and CONFIG_RTE_LINBNAME flags to build a single static DPDK library, named 'libintel_dpdk.a', which OVS links against. Removing the combined library option breaks compatibility with any application that links against the combined DPDK library.
> >
> >Is there a strong technical motivation for removing these options?
> >
> >Thanks,
> >Mark
> From a shared library point of view, it just does not make sense to have
> applications linked against a 'combined' library that may have different
> features built in it.
> 
> Removing these options, aside from the obvious 'less build config option',
> it simplifies maintenance of makefiles as we currently have a separated
> makefile with specific rules just for combined library.
> 
> It is pretty straight forward to build a single combined archive out of
> multiple archives, would it be acceptable to have a script to do this?
> 
> Thanks,
> Sergio
> 
+1

For the static case, its easy to do a post build combination of archives.  For
the shared library case, its equally easy to simply create a linker scripts call
<CONFIG_RTE_LIBNAME>.so that pulls in all the individual libraries.

Neil