[dpdk-dev] [Bug 60] rte_event_port_unlink() causes subsequent events to end up in wrong port

[Maxim Uvarov]

Hello,

is there any progress on this?


Thank you,
Maxim.

On 19.06.2018 12:20, Elo, Matias (Nokia - FI/Espoo) wrote:
>> I think this should handle the unlink case you mention, however perhaps you have identified a genuine bug. If you have more info or a sample config / app that easily demonstrates the issue that would help reproduce/debug here?
>
> Hi Harry,
>
> The bug report includes a simple test application for demonstrating the issue. I've done some further digging and the following simple patch seems to fix the issue of events ending up in wrong ports.
>
>
> diff --git a/drivers/event/sw/sw_evdev_scheduler.c b/drivers/event/sw/sw_evdev_scheduler.c
> index 8a2c9d4f9..57298345d 100644
> --- a/drivers/event/sw/sw_evdev_scheduler.c
> +++ b/drivers/event/sw/sw_evdev_scheduler.c
> @@ -79,9 +79,11 @@ sw_schedule_atomic_to_cq(struct sw_evdev *sw, struct sw_qid * const qid,
>   		int cq = fid->cq;
>   
>   		if (cq < 0) {
> -			uint32_t cq_idx = qid->cq_next_tx++;
> -			if (qid->cq_next_tx == qid->cq_num_mapped_cqs)
> +			uint32_t cq_idx;
> +			if (qid->cq_next_tx >= qid->cq_num_mapped_cqs)
>   				qid->cq_next_tx = 0;
> +			cq_idx = qid->cq_next_tx++;
> +
>   			cq = qid->cq_map[cq_idx];
>   
>   			/* find least used */
> @@ -168,9 +170,11 @@ sw_schedule_parallel_to_cq(struct sw_evdev *sw, struct sw_qid * const qid,
>   		do {
>   			if (++cq_check_count > qid->cq_num_mapped_cqs)
>   				goto exit;
> -			cq = qid->cq_map[cq_idx];
> -			if (++cq_idx == qid->cq_num_mapped_cqs)
> +
> +			if (cq_idx >= qid->cq_num_mapped_cqs)
>   				cq_idx = 0;
> +			cq = qid->cq_map[cq_idx++];
> +
>   		} while (rte_event_ring_free_count(
>   				sw->ports[cq].cq_worker_ring) == 0 ||
>   				sw->ports[cq].inflights == SW_PORT_HIST_LIST);
> @@ -251,6 +255,9 @@ sw_schedule_qid_to_cq(struct sw_evdev *sw)
>   		if (iq_num >= SW_IQS_MAX)
>   			continue;
>   
> +		if (qid->cq_num_mapped_cqs == 0)
> +			continue;
> +
>   		uint32_t pkts_done = 0;
>   		uint32_t count = iq_ring_count(qid->iq[iq_num]);
>
>
> However, events from atomic/ordered queues may still end up getting stuck when unlinking (scheduled back to unlinked port). In case of atomic queues the problem seems to be related to (struct sw_fid_t *)fid->cq fields being invalid. With ordered queues events get stuck in reorder buffer.
>
> -Matias
>