https://dpdk.org/tracker/show_bug.cgi?id=60
Bug ID: 60
Summary: rte_event_port_unlink() causes subsequent events to
end up in wrong port
Product: DPDK
Version: 17.11
Hardware: x86
OS: Linux
Status: CONFIRMED
Severity: major
Priority: Normal
Component: eventdev
Assignee: dev@dpdk.org
Reporter: matias....@nokia.com
Target Milestone: ---
Created attachment 8
--> https://dpdk.org/tracker/attachment.cgi?id=8&action=edit
Test application
I'm seeing some unexpected(?) behavior when calling rte_event_port_unlink()
with the SW eventdev driver (DPDK 17.11.2/18.02.1,
RTE_EVENT_MAX_QUEUES_PER_DEV=255). After calling rte_event_port_unlink(),
the enqueued events may end up either back to the unlinked port or to port
zero.
Scenario:
- Run SW evendev on a service core
- Start eventdev with e.g. 16 ports. Each core will have a dedicated port.
- Create 1 atomic queue and link all active ports to it (some ports may not
be linked).
- Allocate some events and enqueue them to the created queue
- Next, each worker core does a number of scheduling rounds concurrently.
E.g.
uint64_t rx_events = 0;
while(rx_events < SCHED_ROUNDS) {
num_deq = rte_event_dequeue_burst(dev_id, port_id, ev, 1, 0);
if (num_deq) {
rx_events++;
rte_event_enqueue_burst(dev_id, port_id, ev, 1);
}
}
- This works fine but problems occur when doing cleanup after the first
loop finishes on some core.
E.g.
rte_event_port_unlink(dev_id, port_id, NULL, 0);
while(1) {
num_deq = rte_event_dequeue_burst(dev_id, port_id, ev, 1, 0);
if (num_deq == 0)
break;
rte_event_enqueue_burst(dev_id, port_id, ev, 1);
}
- The events enqueued in the cleanup loop will ramdomly end up either back to
the same port (which has already been unlinked) or to port zero, which is not
used (mapping rte_lcore_id to port_id).
As far as I understand the eventdev API, an eventdev port shouldn't have to be
linked to the target queue for enqueue to work properly.
I've attached a simple test application for reproducing this issue.
# sudo ./eventdev --vdev event_sw0 -s 0x2
Below is an example rte_event_dev_dump() output when processing events with two
cores (ports 2 and 3). The rest of the ports are not linked at all but events
still end up to port zero stalling the system.
Regards,
Matias
EventDev todo-fix-name: ports 16, qids 1
rx 908342
drop 0
tx 908342
sched calls: 42577156
sched cq/qid call: 43120490
sched no IQ enq: 42122057
sched no CQ enq: 42122064
inflight 32, credits: 4064
Port 0
rx 0 drop 0 tx 2 inflight 2
Max New: 1024 Avg cycles PP: 0 Credits: 0
Receive burst distribution:
0:-nan%
rx ring used: 0 free: 4096
cq ring used: 2 free: 14
Port 1
rx 0 drop 0 tx 0 inflight 0
Max New: 1024 Avg cycles PP: 0 Credits: 0
Receive burst distribution:
0:-nan%
rx ring used: 0 free: 4096
cq ring used: 0 free: 16
Port 2
rx 524292 drop 0 tx 524290 inflight 0
Max New: 1024 Avg cycles PP: 190 Credits: 30
Receive burst distribution:
0:98% 1-4:1.82%
rx ring used: 0 free: 4096
cq ring used: 0 free: 16
Port 3
rx 384050 drop 0 tx 384050 inflight 0
Max New: 1024 Avg cycles PP: 191 Credits: 0
Receive burst distribution:
0:100% 1-4:0.04%
rx ring used: 0 free: 4096
cq ring used: 0 free: 16
...
Port 15
rx 0 drop 0 tx 0 inflight 0
Max New: 1024 Avg cycles PP: 0 Credits: 0
Receive burst distribution:
0:-nan%
rx ring used: 0 free: 4096
cq ring used: 0 free: 16
Queue 0 (Atomic)
rx 908342 drop 0 tx 908342
Per Port Stats:
Port 0: Pkts: 2 Flows: 1
Port 1: Pkts: 0 Flows: 0
Port 2: Pkts: 524290 Flows: 0
Port 3: Pkts: 384050 Flows: 0
Port 4: Pkts: 0 Flows: 0
Port 5: Pkts: 0 Flows: 0
Port 6: Pkts: 0 Flows: 0
Port 7: Pkts: 0 Flows: 0
Port 8: Pkts: 0 Flows: 0
Port 9: Pkts: 0 Flows: 0
Port 10: Pkts: 0 Flows: 0
Port 11: Pkts: 0 Flows: 0
Port 12: Pkts: 0 Flows: 0
Port 13: Pkts: 0 Flows: 0
Port 14: Pkts: 0 Flows: 0
Port 15: Pkts: 0 Flows: 0
-- iqs empty --
--
You are receiving this mail because:
You are the assignee for the bug.
