Re: [dpdk-dev] [PATCH v4 08/10] examples/l2fwd-event: add eventdev main loop

[Pavan Nikhilesh Bhagavatula <pbhagavatula@marvell.com>]

>>
>> From: Pavan Nikhilesh <pbhagavatula@marvell.com>
>>
>> Add event dev main loop based on enabled l2fwd options and
>eventdev
>> capabilities.
>>
>> Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
>> ---
>
><snip>
>
>> +		if (flags & L2FWD_EVENT_TX_DIRECT) {
>> +			rte_event_eth_tx_adapter_txq_set(mbuf, 0);
>> +			while
>> (!rte_event_eth_tx_adapter_enqueue(event_d_id,
>> +								port_id,
>> +								&ev, 1)
>&&
>> +					!*done)
>> +				;
>> +		}
>
>In the TX direct mode we can send packets directly to the ethernet
>device using ethdev
>API's. This will save unnecessary indirections and event unfolds within
>the driver.

How would we guarantee atomicity of access to Tx queues? Between cores as we can only use one Tx queue. 
Also, if SCHED_TYPE is ORDERED how would we guarantee flow ordering?
The capability of MT_LOCKFREE and flow ordering is abstracted through ` rte_event_eth_tx_adapter_enqueue `.

@see examples/eventdev_pipeline and app/test-eventdev/test_pipeline_*.

>
>> +
>> +		if (timer_period > 0)
>> +			__atomic_fetch_add(&eventdev_rsrc-
>>stats[mbuf-
>> >port].tx,
>> +					   1, __ATOMIC_RELAXED);
>> +	}
>> +}