Re: em(4) multiqueue

On Tue, Jun 16, 2026, at 9:33 AM, Hrvoje Popovski wrote:
> On 25.4.2023. 13:28, Jan Klemkow wrote:
>> On Fri, Apr 14, 2023 at 10:26:14AM +0800, Kevin Lo wrote:
>>> On Thu, Apr 13, 2023 at 01:30:36PM -0500, Brian Conway wrote:
>>>> Reviving this thread, apologies for discontinuity in mail readers: https://marc.info/?t=165642193500008
>>>>
>>>> After rebasing on 7.3, my results have mirrored Hrvoje's testing at
>>>> the end of that thread. No issues with throughput, unusual latency,
>>>> or reliability. `vmstat -i` shows some level of balancing between
>>>> the queues. I've been testing on as many em(4) systems as I have
>>>> access to, some manually, some in a packet forwarder/firewall
>>>> scenarios:
>>> Last time I tested (about a year go) on I211, rx locked up if I tried something
>>> like iperf3 or tcpbench.  Don't know if you have a similar problem.
>> I rebased the rest to current and tested it with tcpbench between the
>> following interfaces:
>> 
>> em0 at pci7 dev 0 function 0 "Intel 82580" rev 0x01, msix, 4 queues, address 90:e2:ba:df:d5:2c
>> em0 at pci5 dev 0 function 0 "Intel I350" rev 0x01, msix, 8 queues, address 00:25:90:eb:b3:c2
>> 
>> After a second the connection stucked.  As far as I can see, the
>> sending side got a problem.
>
> Hi all,
>
> I've searched tech@ for multiqueue em and it seems that this is the last
> mail. Is this still active topic? I've got little supermicro box with
> few onboard em that could be nice box for testing forwarding ...
>
> em0 at pci8 dev 0 function 0 "Intel I210" rev 0x03: msi, address
> em1 at pci9 dev 0 function 0 "Intel I210" rev 0x03: msi, address
> em2 at pci12 dev 0 function 0 "Intel I350" rev 0x01: msi, address
> em3 at pci12 dev 0 function 1 "Intel I350" rev 0x01: msi, address
> em4 at pci12 dev 0 function 2 "Intel I350" rev 0x01: msi, address
> em5 at pci12 dev 0 function 3 "Intel I350" rev 0x01: msi, address

To clarify my quoted message above, I *recall* testing further and seeing the lockups that were described later in the thread:

https://marc.info/?l=openbsd-tech&m=168143921318876&w=2

I have not revisited it since, though, and do not know if the situation has changed since mid-2023.

Brian Conway