Re: DSW eventdev is getting "stuck"?

[Venky Venkatesh <vvenkatesh@paloaltonetworks.com>]

On 4/3/19, 12:02 PM, "Mattias Rönnblom" <mattias.ronnblom@ericsson.com> wrote:

    On 2019-04-03 20:36, Venky Venkatesh wrote:
    > 
    > 
    > On 4/3/19, 11:34 AM, "Mattias Rönnblom" <mattias.ronnblom@ericsson.com> wrote:
    > 
    >      On 2019-04-03 20:17, Venky Venkatesh wrote:
    >      > Hi,
    >      > I am using the DSW code from 18.11 with the default settings for all the #defines. Here are some more details:
    >      > I have an 8 port system with 1 queue.
    >      > All ports can inject events. Port 0 and 7 inject events rarely.
    >      > Ports 1-6 are linked to the queue and hence dequeue events.
    >      >
    >      > I see that in steady state the total number enqueues into the system is much greater than the total number of dequeues.
    >      > eventdev deq#: 1948491 enq#: 1949007
    >      >
    >      
    >      If you have more enqueues than dequeues, it means there are events in
    >      flight in the scheduler. In the above case, it's roughly 516 events,
    >      which sounds perfectly healthy and normal. I say roughly, because
    >      there's no way to take a consistent, global snapshot of all xstats counters.
    > 
    > [VV]: This is in steady state i.e. there are no more events being injected into the system. So shouldn’t everything get drained out at some point?
    >      
    
    Assuming appropriate application behavior, sure, of course.
    
    Events in flight are either in the output buffer on the producer port, 
    or the input ring on the consumer.
    
    Inappropriate behavior would be if any port (producer, consumer or 
    producer+consumer) is left unattended (i.e. no enqueue or dequeue 
    operation is performed).

[VV]: I am pasting the original data again below. If about 516 events are inflight, atleast a few should show up in one of the data structures that you refer to -- but they don’t as seen below. Isn't that odd? Do you have any other places I can look -- there were no migrations too to look at some other transient buffers.

Below are the counters:
 
[root@PA-VM-venky ~]# cat y
      dev_credits_on_loan:                 883
------ port 0 --------
      port_0_new_enqueued:                 125
  port_0_forward_enqueued:                   0
  port_0_release_enqueued:                   0
  port_0_queue_0_enqueued:                 125
          port_0_dequeued:                   0
  port_0_queue_0_dequeued:                   0
        port_0_migrations:                   0
 port_0_migration_latency:                   0
port_0_event_proc_latency:                   0
  port_0_inflight_credits:                   3
              port_0_load:                  49
           port_0_last_bg:      39368511869708
------ port 1 --------
      port_1_new_enqueued:              138947
  port_1_forward_enqueued:              237896
  port_1_release_enqueued:                   0
  port_1_queue_0_enqueued:              376843
          port_1_dequeued:              475778
  port_1_queue_0_dequeued:              475778
        port_1_migrations:                   0
 port_1_migration_latency:                   0
port_1_event_proc_latency:              119069
  port_1_inflight_credits:                  13
              port_1_load:                   0
           port_1_last_bg:      77183632541672
------ port 2 --------
      port_2_new_enqueued:               88834
  port_2_forward_enqueued:              156687
  port_2_release_enqueued:                   0
  port_2_queue_0_enqueued:              245521
          port_2_dequeued:              313358
  port_2_queue_0_dequeued:              313358
        port_2_migrations:                   0
 port_2_migration_latency:                   0
port_2_event_proc_latency:              176184
  port_2_inflight_credits:                  15
              port_2_load:                   0
           port_2_last_bg:      77183632941696
------ port 3 --------
      port_3_new_enqueued:               73170
  port_3_forward_enqueued:               78087
  port_3_release_enqueued:                   0
  port_3_queue_0_enqueued:              151257
          port_3_dequeued:              165317
  port_3_queue_0_dequeued:              165317
        port_3_migrations:                   0
 port_3_migration_latency:                   0
port_3_event_proc_latency:              329601
  port_3_inflight_credits:                  66
              port_3_load:                   0
           port_3_last_bg:      77183632966910
------ port 4 --------
      port_4_new_enqueued:               93182
  port_4_forward_enqueued:               76422
  port_4_release_enqueued:                   0
  port_4_queue_0_enqueued:              169604
          port_4_dequeued:              207721
  port_4_queue_0_dequeued:              207721
        port_4_migrations:                   0
 port_4_migration_latency:                   0
port_4_event_proc_latency:              262259
  port_4_inflight_credits:                 114
              port_4_load:                   0
           port_4_last_bg:      77183632760588
------ port 5 --------
      port_5_new_enqueued:              144855
  port_5_forward_enqueued:              630897
  port_5_release_enqueued:                   0
  port_5_queue_0_enqueued:              775752
          port_5_dequeued:              633700
  port_5_queue_0_dequeued:              633700
        port_5_migrations:                   0
 port_5_migration_latency:                   0
port_5_event_proc_latency:               88203
  port_5_inflight_credits:                  64
              port_5_load:                   0
           port_5_last_bg:      77183632277448
------ port 6 --------
      port_6_new_enqueued:              153590
  port_6_forward_enqueued:               76315
  port_6_release_enqueued:                   0
  port_6_queue_0_enqueued:              229905
          port_6_dequeued:              152617
  port_6_queue_0_dequeued:              152617
        port_6_migrations:                   0
 port_6_migration_latency:                   0
port_6_event_proc_latency:              354408
  port_6_inflight_credits:                  92
              port_6_load:                   0
           port_6_last_bg:      77183632653092
------ port 7 --------
      port_7_new_enqueued:                   0
  port_7_forward_enqueued:                   0
  port_7_release_enqueued:                   0
  port_7_queue_0_enqueued:                   0
          port_7_dequeued:                   0
  port_7_queue_0_dequeued:                   0
        port_7_migrations:                   0
 port_7_migration_latency:                   0
port_7_event_proc_latency:                   0
  port_7_inflight_credits:                   0
              port_7_load:                   0
 
 
 
Below are the data structure values:
 
(gdb) p ((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[0]->out_buffer_len
$2 = {0 <repeats 64 times>}
(gdb) p ((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[1]->out_buffer_len
$3 = {0 <repeats 64 times>}
(gdb) p ((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[2]->out_buffer_len
$4 = {0 <repeats 64 times>}
(gdb) p ((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[3]->out_buffer_len
$5 = {0 <repeats 64 times>}
(gdb) p ((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[4]->out_buffer_len
$6 = {0 <repeats 64 times>}
(gdb) p ((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[5]->out_buffer_len
$7 = {0 <repeats 64 times>}
(gdb) p ((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[6]->out_buffer_len
$8 = {0 <repeats 64 times>}
(gdb) p ((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[7]->out_buffer_len
$9 = {0 <repeats 64 times>}
(gdb) p *((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[0]->in_ring
$10 = {r = {name = "dsw0_p0", '\000' <repeats 24 times>, flags = 6, memzone = 0xc000000090, size = 32768, mask = 32767, capacity = 16384, pad0 = 0 '\000', prod = {head = 0, tail = 0, 
      single = 0}, pad1 = 0 '\000', cons = {head = 0, tail = 0, single = 1}, pad2 = 0 '\000'}}
(gdb) p *((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[1]->in_ring
$11 = {r = {name = "dsw0_p1", '\000' <repeats 24 times>, flags = 6, memzone = 0xc000000120, size = 32768, mask = 32767, capacity = 16384, pad0 = 0 '\000', prod = {head = 475778, 
      tail = 475778, single = 0}, pad1 = 0 '\000', cons = {head = 475778, tail = 475778, single = 1}, pad2 = 0 '\000'}}
(gdb) p *((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[2]->in_ring
$12 = {r = {name = "dsw0_p2", '\000' <repeats 24 times>, flags = 6, memzone = 0xc0000001b0, size = 32768, mask = 32767, capacity = 16384, pad0 = 0 '\000', prod = {head = 313358, 
      tail = 313358, single = 0}, pad1 = 0 '\000', cons = {head = 313358, tail = 313358, single = 1}, pad2 = 0 '\000'}}
(gdb) p *((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[3]->in_ring
$13 = {r = {name = "dsw0_p3", '\000' <repeats 24 times>, flags = 6, memzone = 0xc000000240, size = 32768, mask = 32767, capacity = 16384, pad0 = 0 '\000', prod = {head = 165403, 
      tail = 165403, single = 0}, pad1 = 0 '\000', cons = {head = 165403, tail = 165403, single = 1}, pad2 = 0 '\000'}}
(gdb) p *((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[4]->in_ring
$14 = {r = {name = "dsw0_p4", '\000' <repeats 24 times>, flags = 6, memzone = 0xc0000002d0, size = 32768, mask = 32767, capacity = 16384, pad0 = 0 '\000', prod = {head = 208237, 
      tail = 208237, single = 0}, pad1 = 0 '\000', cons = {head = 208237, tail = 208237, single = 1}, pad2 = 0 '\000'}}
(gdb) p *((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[5]->in_ring
$15 = {r = {name = "dsw0_p5", '\000' <repeats 24 times>, flags = 6, memzone = 0xc000000360, size = 32768, mask = 32767, capacity = 16384, pad0 = 0 '\000', prod = {head = 633700, 
      tail = 633700, single = 0}, pad1 = 0 '\000', cons = {head = 633700, tail = 633700, single = 1}, pad2 = 0 '\000'}}
(gdb) p *((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[6]->in_ring
$16 = {r = {name = "dsw0_p6", '\000' <repeats 24 times>, flags = 6, memzone = 0xc0000003f0, size = 32768, mask = 32767, capacity = 16384, pad0 = 0 '\000', prod = {head = 152617, 
      tail = 152617, single = 0}, pad1 = 0 '\000', cons = {head = 152617, tail = 152617, single = 1}, pad2 = 0 '\000'}}
(gdb) p *((struct dsw_evdev *)rte_eventdevs[0].data->dev_private)->ports[7]->in_ring
$17 = {r = {name = "dsw0_p7", '\000' <repeats 24 times>, flags = 6, memzone = 0xc000000480, size = 32768, mask = 32767, capacity = 16384, pad0 = 0 '\000', prod = {head = 0, tail = 0, 
      single = 0}, pad1 = 0 '\000', cons = {head = 0, tail = 0, single = 1}, pad2 = 0 '\000'}}