Re: [dpdk-dev] [PATCH v1] app/test: zcd needs to be initialised to fix gcc compile error

["Walsh, Conor" <conor.walsh@intel.com>]

> From: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
> Sent: Monday 9 November 2020 22:44
> To: Walsh, Conor <conor.walsh@intel.com>; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>
> Cc: dev@dpdk.org; Chen, LingliX <linglix.chen@intel.com>; nd
> <nd@arm.com>; Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>;
> nd <nd@arm.com>
> Subject: RE: [PATCH v1] app/test: zcd needs to be initialised to fix gcc compile
> error
> 
> <snip>
> 
> > >
> > > >
> > > > [2339/2407] Compiling C object app/test/dpdk-
> > > > test.p/test_ring_mt_peek_stress_zc.c.o
> > > > FAILED: app/test/dpdk-test.p/test_ring_mt_peek_stress_zc.c.o
> > > > gcc -Iapp/test/dpdk-test.p -Iapp/test -I../app/test -Ilib/librte_acl
> > > > - I../lib/librte_acl -I. -I.. -Iconfig -I../config
> > > > -Ilib/librte_eal/include - I../lib/librte_eal/include
> > > > -Ilib/librte_eal/linux/include - I../lib/librte_eal/linux/include
> > > > -Ilib/librte_eal/x86/include - I../lib/librte_eal/x86/include
> > > > -Ilib/librte_eal/common - I../lib/librte_eal/common -Ilib/librte_eal
> > > > -I../lib/librte_eal -
> > > Ilib/librte_kvargs -
> > > > I../lib/librte_kvargs -Ilib/librte_metrics -I../lib/librte_metrics -
> > > > Ilib/librte_telemetry -I../lib/librte_telemetry -Idrivers/bus/pci -
> > > > I../drivers/bus/pci -I../drivers/bus/pci/linux -Ilib/librte_pci
> > > > -I../lib/librte_pci
> > > -
> > > > Idrivers/bus/vdev -I../drivers/bus/vdev -Ilib/librte_bitratestats -
> > > > I../lib/librte_bitratestats -Ilib/librte_ethdev
> > > > -I../lib/librte_ethdev - Ilib/librte_net -I../lib/librte_net
> > > > -Ilib/librte_mbuf -I../lib/librte_mbuf - Ilib/librte_mempool
> > > > -I../lib/librte_mempool -Ilib/librte_ring -
> > > I../lib/librte_ring
> > > > -Ilib/librte_meter -I../lib/librte_meter -Ilib/librte_bpf
> > > > -I../lib/librte_bpf - Ilib/librte_cfgfile -I../lib/librte_cfgfile
> > > > -Ilib/librte_cmdline -
> > > I../lib/librte_cmdline
> > > > -Ilib/librte_cryptodev -I../lib/librte_cryptodev
> > > > -Ilib/librte_distributor - I../lib/librte_distributor
> > > > -Ilib/librte_efd -I../lib/librte_efd -Ilib/librte_hash -
> > > > I../lib/librte_hash -Ilib/librte_rcu -I../lib/librte_rcu
> > > > -Ilib/librte_eventdev - I../lib/librte_eventdev -Ilib/librte_timer
> > > > -I../lib/librte_timer -Ilib/librte_fib - I../lib/librte_fib
> > > > -Ilib/librte_rib -I../lib/librte_rib -Ilib/librte_flow_classify -
> > > > I../lib/librte_flow_classify -Ilib/librte_table
> > > > -I../lib/librte_table -
> > > Ilib/librte_port
> > > > -I../lib/librte_port -Ilib/librte_sched -I../lib/librte_sched
> > > > -Ilib/librte_ip_frag
> > > -
> > > > I../lib/librte_ip_frag -Ilib/librte_kni -I../lib/librte_kni
> > > > -Ilib/librte_lpm - I../lib/librte_lpm -Ilib/librte_graph
> > > > -I../lib/librte_graph -Ilib/librte_ipsec - I../lib/librte_ipsec
> > > > -Ilib/librte_security -I../lib/librte_security -
> > > > Ilib/librte_latencystats -I../lib/librte_latencystats
> > > > -Ilib/librte_member - I../lib/librte_member -Ilib/librte_node
> > > > -I../lib/librte_node -
> > > Ilib/librte_pipeline
> > > > -I../lib/librte_pipeline -Ilib/librte_rawdev -I../lib/librte_rawdev
> > > > - Ilib/librte_reorder -I../lib/librte_reorder -Ilib/librte_stack -
> > > I../lib/librte_stack -
> > > > Idrivers/mempool/ring -I../drivers/mempool/ring
> > > > -Idrivers/mempool/stack
> > > -
> > > > I../drivers/mempool/stack -Idrivers/event/skeleton -
> > > > I../drivers/event/skeleton -Idrivers/net/bonding
> > > > -I../drivers/net/bonding - Idrivers/net/ring -I../drivers/net/ring
> > > > -Ilib/librte_power -
> > > I../lib/librte_power -
> > > > Ilib/librte_pdump -I../lib/librte_pdump -Idrivers/crypto/scheduler -
> > > > I../drivers/crypto/scheduler -fdiagnostics-color=always -pipe -
> > > > D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Werror -O1 -include
> > > > rte_config.h -Wextra -Wcast-qual -Wdeprecated -Wformat-nonliteral -
> > > > Wformat-security -Wmissing-declarations -Wmissing-prototypes -
> > > Wnested-
> > > > externs -Wold-style-definition -Wpointer-arith -Wsign-compare
> > > > -Wstrict- prototypes -Wundef -Wwrite-strings -Wno-packed-not-
> aligned
> > > > -Wno-
> > > missing-
> > > > field-initializers -march=native -mno-avx512f -
> > > DALLOW_EXPERIMENTAL_API -
> > > > Wno-format-truncation -D_GNU_SOURCE -fno-strict-aliasing -
> > > > DALLOW_INTERNAL_API -MD -MQ app/test/dpdk-
> > > > test.p/test_ring_mt_peek_stress_zc.c.o -MF app/test/dpdk-
> > > > test.p/test_ring_mt_peek_stress_zc.c.o.d -o app/test/dpdk-
> > > > test.p/test_ring_mt_peek_stress_zc.c.o -c
> > > > ../app/test/test_ring_mt_peek_stress_zc.c
> > > > ../app/test/test_ring_mt_peek_stress_zc.c: In function
> > > > '_st_ring_dequeue_bulk':
> > > > ../app/test/test_ring_mt_peek_stress_zc.c:13:11: error: variable 'm'
> > > > set
> > > but
> > > > not used [-Werror=unused-but-set-variable]
> > > >   uint32_t m;
> > > >            ^
> > > > ../app/test/test_ring_mt_peek_stress_zc.c: In function
> > > > '_st_ring_enqueue_bulk':
> > > > ../app/test/test_ring_mt_peek_stress_zc.c:31:11: error: variable 'm'
> > > > set
> > > but
> > > > not used [-Werror=unused-but-set-variable]
> > > >   uint32_t m;
> > > >            ^
> > > I am not sure why you are seeing the above error.
> >
> > m is being set but is only being used in the line that I commented out, if
> that
> > line needs to be removed then m doesn't need to be set or declared.
> > E.g. below.
> >
> > test_ring_mt_peek_stress_zc.c:9
> > static inline uint32_t
> > _st_ring_dequeue_bulk(struct rte_ring *r, void **obj, uint32_t n,
> >         uint32_t *avail)
> > {
> >         uint32_t m;
> >         struct rte_ring_zc_data zcd;
> >
> >         m = rte_ring_dequeue_zc_bulk_start(r, n, &zcd, avail);
> >         //n = (m == n) ? n : 0;
> >         if (n != 0) {
> Sorry, the above 'if' statement should be as follows:
> if (m != 0) {

Thanks Honnappa, those two changes fix the issue for me.
I will send a V2 of the patch with these changes.

Thanks,
Conor.

> 
> >                 /* Copy the data from the ring */
> >                 test_ring_copy_from(&zcd, obj, -1, n);
> >                 rte_ring_dequeue_zc_finish(r, n);
> >         }
> >
> >         return n;
> > }
> >
> > Thanks for looking into this.
> >
> > >
> > > <snip>