RE: [EXTERNAL] [PATCH] examples/l3fwd: fix Rx over not ready port

[Konstantin Ananyev <konstantin.ananyev@huawei.com>]

> > From: Konstantin Ananyev <konstantin.v.ananyev@yandex.ru>
> > Sent: Friday, March 1, 2024 10:10 PM
> > To: dev@dpdk.org
> > Cc: Jerin Jacob <jerinj@marvell.com>; Pavan Nikhilesh Bhagavatula
> > <pbhagavatula@marvell.com>; Konstantin Ananyev
> > <konstantin.ananyev@huawei.com>; stable@dpdk.org
> > Subject: [EXTERNAL] [PATCH] examples/l3fwd: fix Rx over not ready port
> >
> > Prioritize security for external emails: Confirm sender and content safety
> > before clicking links or opening attachments
> >
> > ----------------------------------------------------------------------
> > From: Konstantin Ananyev <konstantin.ananyev@huawei.com>
> >
> > Running l3fwd in event mode with SW eventdev, service cores
> > can start RX before main thread is finished with PMD installation.
> > to reproduce:
> > ./dpdk-l3fwd --lcores=49,51 -n 6 -a ca:00.0 -s 0x8000000000000 \
> > --vdev event_sw0 -- \
> > -L -P -p 1  --mode eventdev --eventq-sched=ordered \
> > --rule_ipv4=test/l3fwd_lpm_v4_u1.cfg --rule_ipv6=test/l3fwd_lpm_v6_u1.cfg
> > \
> > --no-numa
> >
> > At init stage user will most likely see the error message like that:
> > ETHDEV: lcore 51 called rx_pkt_burst for not ready port 0
> > 0: ./dpdk-l3fwd (rte_dump_stack+0x1f) [15de723]
> > ...
> > 9: ./dpdk-l3fwd (eal_thread_loop+0x5a2) [15c1324]
> > ...
> >
> > And then all depends how luck/unlucky you are.
> > If there are some actual packet in HW RX queue, then the app will most
> > likely crash, otherwise it might survive.
> > As error message suggests, the problem is that services are started
> > before main thread finished with NIC setup and initialization.
> > The suggested fix moves services startup after NIC setup phase.
> >
> > Bugzilla ID: 1390
> > Fixes: 8bd537e9c6cf ("examples/l3fwd: add service core setup based on
> > caps")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Konstantin Ananyev <konstantin.v.ananyev@yandex.ru>
> > Signed-off-by: Konstantin Ananyev <konstantin.ananyev@huawei.com>
> > ---
> >  examples/l3fwd/main.c | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/examples/l3fwd/main.c b/examples/l3fwd/main.c
> > index 3bf28aec0c..d4fb5d1971 100644
> > --- a/examples/l3fwd/main.c
> > +++ b/examples/l3fwd/main.c
> > @@ -1577,7 +1577,6 @@ main(int argc, char **argv)
> >  			l3fwd_lkp.main_loop = evt_rsrc->ops.fib_event_loop;
> >  		else
> >  			l3fwd_lkp.main_loop = evt_rsrc-
> > >ops.lpm_event_loop;
> > -		l3fwd_event_service_setup();
> >  	} else
> >  #endif
> >  		l3fwd_poll_resource_setup();
> > @@ -1609,6 +1608,11 @@ main(int argc, char **argv)
> >  		}
> >  	}
> >
> > +#ifdef RTE_LIB_EVENTDEV
> 
> Is the ifdef required?

Well, right now l3fwd_event_service_setup() is defined only when
RTE_LIB_EVENTDEV is defined, see examples/l3fwd/main.c.
So, I suppose, yes.

> 
> > +	if (evt_rsrc->enabled)
> > +		l3fwd_event_service_setup();
> > +#endif
> > +
> >  	printf("\n");
> >
> >  	for (lcore_id = 0; lcore_id < RTE_MAX_LCORE; lcore_id++) {
> > --
> > 2.35.3