Intel ix staled under heavy load

[Slawa Olhovchenkov]

On Wed, Jan 15, 2020 at 09:41:06AM +0100, Hans Petter Selasky wrote:

> On 2020-01-14 19:26, Nick Rogers wrote:
> > On Tue, Jan 14, 2020 at 10:09 AM Hans Petter Selasky <hps at selasky.org>
> > wrote:
> > 
> >> On 2020-01-14 16:07, Slawa Olhovchenkov wrote:
> >>>> this is a known issue in iflib.
> >>> Unresolved?
> >>
> >> See mail I sent off-list.
> >>
> > 
> > I would be interested to know if this is resolved or not as well.
> > 
> 
> No, not yet.
> 
> Slawa, can you dump the iflib sysctl's when the card is in the stalled 
> state?

I am see individual stalled RX queue.
For this case:

a) rxd_tail == rxd_head (in normal case w/o traffic rxd_tail == rxd_head-1)
b) rxq_fl0.cidx == rxd_tail (in normal case w/o traffic rxq_fl0.cidx == rxd_head)

For example1:

# sysctl dev.ix | grep -e rxd_ -e rxq_fl0.cidx
dev.ix.1.queue3.rxd_tail: 1693
dev.ix.1.queue3.rxd_head: 1694
dev.ix.1.queue2.rxd_tail: 1917
dev.ix.1.queue2.rxd_head: 1918
dev.ix.1.queue1.rxd_tail: 1628
dev.ix.1.queue1.rxd_head: 1629
dev.ix.1.queue0.rxd_tail: 161
dev.ix.1.queue0.rxd_head: 162
dev.ix.1.iflib.rxq3.rxq_fl0.cidx: 1694
dev.ix.1.iflib.rxq2.rxq_fl0.cidx: 1918
dev.ix.1.iflib.rxq1.rxq_fl0.cidx: 1629
dev.ix.1.iflib.rxq0.rxq_fl0.cidx: 162
dev.ix.0.queue3.rxd_tail: 1141
dev.ix.0.queue3.rxd_head: 1142
dev.ix.0.queue2.rxd_tail: 1598
dev.ix.0.queue2.rxd_head: 1598
                   ^^^^^^^^^^^
dev.ix.0.queue1.rxd_tail: 720
dev.ix.0.queue1.rxd_head: 721
dev.ix.0.queue0.rxd_tail: 1356
dev.ix.0.queue0.rxd_head: 1356
                       ^^^^^^^
dev.ix.0.iflib.rxq3.rxq_fl0.cidx: 1142
dev.ix.0.iflib.rxq2.rxq_fl0.cidx: 1598
dev.ix.0.iflib.rxq1.rxq_fl0.cidx: 721
dev.ix.0.iflib.rxq0.rxq_fl0.cidx: 1356

For example2:

# sysctl dev.ix | grep -e rxd_ -e rxq_fl0.cidx
dev.ix.0.queue3.rxd_tail: 205
dev.ix.0.queue3.rxd_head: 240
dev.ix.0.queue2.rxd_tail: 1566
dev.ix.0.queue2.rxd_head: 1566
                ^^^^^^^^^^^^^^
dev.ix.0.queue1.rxd_tail: 1371
dev.ix.0.queue1.rxd_head: 1456
dev.ix.0.queue0.rxd_tail: 1120
dev.ix.0.queue0.rxd_head: 1120
                    ^^^^^^^^^^
dev.ix.0.iflib.rxq3.rxq_fl0.cidx: 708
dev.ix.0.iflib.rxq2.rxq_fl0.cidx: 1566
dev.ix.0.iflib.rxq1.rxq_fl0.cidx: 1764
dev.ix.0.iflib.rxq0.rxq_fl0.cidx: 1120