Re: [dpdk-dev] [PATCH v2 10/11] examples/l3fwd: add graceful teardown for eventdevice

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> >> Add graceful teardown that addresses both event mode and poll
> >mode.
> >>
> >> Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
> >> ---
> >>  examples/l3fwd/main.c | 49 ++++++++++++++++++++++++++++++-
> >------------
> >>  1 file changed, 34 insertions(+), 15 deletions(-)
> >>
> >> diff --git a/examples/l3fwd/main.c b/examples/l3fwd/main.c
> >> index 0ae64dd41..68998f42c 100644
> >> --- a/examples/l3fwd/main.c
> >> +++ b/examples/l3fwd/main.c
> >> @@ -920,7 +920,7 @@ main(int argc, char **argv)
> >>  	struct lcore_conf *qconf;
> >>  	struct rte_eth_dev_info dev_info;
> >>  	struct rte_eth_txconf *txconf;
> >> -	int ret;
> >> +	int i, ret;
> >>  	unsigned nb_ports;
> >>  	uint16_t queueid, portid;
> >>  	unsigned lcore_id;
> >> @@ -1195,27 +1195,46 @@ main(int argc, char **argv)
> >>  		}
> >>  	}
> >>
> >> -
> >>  	check_all_ports_link_status(enabled_port_mask);
> >>
> >>  	ret = 0;
> >>  	/* launch per-lcore init on every lcore */
> >>  	rte_eal_mp_remote_launch(l3fwd_lkp.main_loop, NULL,
> >CALL_MASTER);
> >> -	RTE_LCORE_FOREACH_SLAVE(lcore_id) {
> >> -		if (rte_eal_wait_lcore(lcore_id) < 0) {
> >> -			ret = -1;
> >> -			break;
> >> +	if (evt_rsrc->enabled) {
> >> +		for (i = 0; i < evt_rsrc->rx_adptr.nb_rx_adptr; i++)
> >> +			rte_event_eth_rx_adapter_stop(
> >> +					evt_rsrc->rx_adptr.rx_adptr[i]);
> >> +		for (i = 0; i < evt_rsrc->tx_adptr.nb_tx_adptr; i++)
> >> +			rte_event_eth_tx_adapter_stop(
> >> +					evt_rsrc->tx_adptr.tx_adptr[i]);
> >> +
> >> +		RTE_ETH_FOREACH_DEV(portid) {
> >> +			if ((enabled_port_mask & (1 << portid)) == 0)
> >> +				continue;
> >> +			rte_eth_dev_stop(portid);
> >>  		}
> >> -	}
> >>
> >> -	/* stop ports */
> >> -	RTE_ETH_FOREACH_DEV(portid) {
> >> -		if ((enabled_port_mask & (1 << portid)) == 0)
> >> -			continue;
> >> -		printf("Closing port %d...", portid);
> >> -		rte_eth_dev_stop(portid);
> >> -		rte_eth_dev_close(portid);
> >> -		printf(" Done\n");
> >
> >Why to stop ports *before* making sure all lcores are stopped?
> >Shouldn't that peace of code be identical for both poll and event mode?
> >Something like:
> >rte_eal_mp_wait_lcore();
> >
> >                RTE_ETH_FOREACH_DEV(portid) {
> >                        if ((enabled_port_mask & (1 << portid)) == 0)
> >                                continue;
> >                        rte_eth_dev_stop(portid);
> >                        rte_eth_dev_close(portid);
> >                }
> >?
> >
> 
> Event dev spec requires stopping producers before consumers else we might run into
> deadlock in some cases.

Ok... but for TX path wouldn't core be a producer?
Also for that wouldn't rte_event_eth_(rx|tx)_adapter_stop(0 be enough?
I am not familiar with event-dev spec at all, so forgive for possibly dumb questions 😉

> 
> >> +		rte_eal_mp_wait_lcore();
> >> +		RTE_ETH_FOREACH_DEV(portid) {
> >> +			if ((enabled_port_mask & (1 << portid)) == 0)
> >> +				continue;
> >> +			rte_eth_dev_close(portid);
> >> +		}
> >> +
> >> +		rte_event_dev_stop(evt_rsrc->event_d_id);
> >> +		rte_event_dev_close(evt_rsrc->event_d_id);
> >> +
> >> +	} else {
> >> +		rte_eal_mp_wait_lcore();
> >> +
> >> +		RTE_ETH_FOREACH_DEV(portid) {
> >> +			if ((enabled_port_mask & (1 << portid)) == 0)
> >> +				continue;
> >> +			printf("Closing port %d...", portid);
> >> +			rte_eth_dev_stop(portid);
> >> +			rte_eth_dev_close(portid);
> >> +			printf(" Done\n");
> >> +		}
> >>  	}
> >>  	printf("Bye...\n");
> >>
> >> --
> >> 2.17.1