[dpdk-dev] [PATCH v3 09/12] app/eventdev: add pipeline queue worker functions

[Van Haaren, Harry]

> From: Pavan Nikhilesh [mailto:pbhagavatula at caviumnetworks.com]
> Sent: Wednesday, January 10, 2018 2:52 PM
> To: jerin.jacob at caviumnetworks.com; santosh.shukla at caviumnetworks.com; Van
> Haaren, Harry <harry.van.haaren at intel.com>; Eads, Gage
> <gage.eads at intel.com>; hemant.agrawal at nxp.com; nipun.gupta at nxp.com; Ma,
> Liang J <liang.j.ma at intel.com>
> Cc: dev at dpdk.org; Pavan Nikhilesh <pbhagavatula at caviumnetworks.com>
> Subject: [dpdk-dev] [PATCH v3 09/12] app/eventdev: add pipeline queue worker
> functions
> 

<snip>


> +static __rte_always_inline void
> +pipeline_tx_pkt_safe(struct rte_mbuf *mbuf)
> +{
> +	while (rte_eth_tx_burst(mbuf->port, 0, &mbuf, 1) != 1)
> +		rte_pause();
> +}

re safe, see comment below

> +
> +static __rte_always_inline void
> +pipeline_tx_pkt_unsafe(struct rte_mbuf *mbuf, struct test_pipeline *t)
> +{
> +	rte_spinlock_t *lk = &t->tx_lk[mbuf->port];
> +
> +	rte_spinlock_lock(lk);
> +	pipeline_tx_pkt_safe(mbuf);
> +	rte_spinlock_unlock(lk);
> +}

IIRC usually the "Safe" version of a function has extra locks/protection, while the "normal" version has better performance, but less-error-checking.

Here, the "unsafe" function does the extra locking. If looking from the HW POV, that makes sense, but I think its inverted from most existing code...

Happy to be proved wrong here .. ?

<snip>

> +static int
> +pipeline_queue_worker_single_stage_safe(void *arg)
> +{
> +	struct worker_data *w  = arg;
> +	struct test_pipeline *t = w->t;
> +	const uint8_t dev = w->dev_id;
> +	const uint8_t port = w->port_id;
> +	struct rte_event ev;
> +
> +	while (t->done == false) {
> +		uint16_t event = rte_event_dequeue_burst(dev, port, &ev, 1, 0);
> +
> +		if (!event) {
> +			rte_pause();
> +			continue;
> +		}
> +
> +		if (ev.sched_type == RTE_SCHED_TYPE_ATOMIC) {
> +			pipeline_tx_pkt_safe(ev.mbuf);

I guess that means that the functions where they're used are inverted in name too.

<snip>