On Tue, 16 Jul 2019 09:46:04 +0100
Bruce Richardson <bruce.richard...@intel.com> wrote:
> On Mon, Jul 15, 2019 at 05:19:12PM -0700, Stephen Hemminger wrote:
> > On Mon, 15 Jul 2019 16:41:36 -0700
> > Stephen Hemminger <step...@networkplumber.org> wrote:
> >
> > > If DPDK is built as a shared library, then any application linked
> > > with rte.app.mk will not find any PCI devices. When the application
> > > is started no ethernet devices are found.
> > >
> > > This is because the link order of libraries on the command line matters.
> > > And PCI is before EAL. That causes there to be no dependency on PCI
> > > so linker ignores linking the library.
> > > Swapping the order fixes this.
> > >
> > > Fixes: c752998b5e2e ("pci: introduce library and driver")
> > > Cc: sta...@dpdk.org
> > > Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
> > > ---
> > > mk/rte.app.mk | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/mk/rte.app.mk b/mk/rte.app.mk
> > > index a277c808ed8e..470b92e4d73e 100644
> > > --- a/mk/rte.app.mk
> > > +++ b/mk/rte.app.mk
> > > @@ -90,8 +90,8 @@ _LDLIBS-$(CONFIG_RTE_LIBRTE_STACK) +=
> > > -lrte_stack
> > > _LDLIBS-$(CONFIG_RTE_DRIVER_MEMPOOL_RING) += -lrte_mempool_ring
> > > _LDLIBS-$(CONFIG_RTE_LIBRTE_OCTEONTX2_MEMPOOL) += -lrte_mempool_octeontx2
> > > _LDLIBS-$(CONFIG_RTE_LIBRTE_RING) += -lrte_ring
> > > -_LDLIBS-$(CONFIG_RTE_LIBRTE_PCI) += -lrte_pci
> > > _LDLIBS-$(CONFIG_RTE_LIBRTE_EAL) += -lrte_eal
> > > +_LDLIBS-$(CONFIG_RTE_LIBRTE_PCI) += -lrte_pci
> > > _LDLIBS-$(CONFIG_RTE_LIBRTE_CMDLINE) += -lrte_cmdline
> > > _LDLIBS-$(CONFIG_RTE_LIBRTE_REORDER) += -lrte_reorder
> > > _LDLIBS-$(CONFIG_RTE_LIBRTE_SCHED) += -lrte_sched
> >
> > It still happens with 19.08. Testpmd works but only because it is
> > linked with so many things. But l3fwd fails...
> >
> > # ./examples/l3fwd/build/l3fwd -n4 -l0-3 -w 02:00.0
> > EAL: Detected 8 lcore(s)
> > EAL: Detected 1 NUMA nodes
> > EAL: failed to parse device "02:00.0"
> > EAL: Unable to parse device '02:00.0'
> > EAL: Error - exiting with code: 1
> > Cause: Invalid EAL parameters
>
> I don't think the position of these is going to be the cause here, the more
> likely cause is that the pci bus driver - and all other drivers - are not
> linked into apps for shared library builds. You always need to pass "-d"
> parameter to load drivers at init time (or have them installed in the
> correct driver path). For example, for me with a shared library build the
> following gives a no ports error:
>
> sudo ./build/l2fwd -c F00000 -- -p 3
>
> while this succeeds and runs fine
>
> sudo ./build/l2fwd -c F00000 -d
> $RTE_SDK/$RTE_TARGET/lib/librte_pmd_i40e.so -- -p 3
The root cause is that recent gcc won't run constructor on unused libraries.
Testing a patch to take --as-needed off of PCI library.
See:
https://stackoverflow.com/questions/11631161/force-to-link-against-unused-shared-library
