[REGRESSION] Fresh CURRENT consume much more CPU on network traffic (vlans + routing + ipfw with NAT)

[Kevin Bowling]

This sounds like a known quirk of the Atom CPU architecture and iflib
-- can you try this patch https://reviews.freebsd.org/D16302 it should
help specifically on your hardware.

Regards,
Kevin

On Tue, Jul 17, 2018 at 6:03 AM, Lev Serebryakov <lev at freebsd.org> wrote:
> On 17.07.2018 10:54, Eugene Grosbein wrote:
>
>>>  I have "SOHO" router on Atom D2500 with FreeBSD CURRENT. It runs
>>> CURRENT for very long time (from 11-CURRENT times), and recently it
>>> start to consume much more CPU on same traffic — to the point when it
>>> becomes unresponsive in shell (via ssh, not local console).
>>>
>>>  I have rather complex ipfw ruleset, but this ruleset is the same for
>>> many years.
>>>
>>>  Revisions before r333989 worked normally, I never seen any problem with
>>> shell, no matter how much traffic is processed
>>>
>>>  Revision r334649 with same configuration, same firewall ruleset, etc.,
>>> becomes completely unresponsive under network load (pure transit traffic).
>>>
>>>  when system is unresponsive I see this in `top -SH`
>>>
>>> 100083 root -76 - 0K   272K -       1 291.8H  95.31% kernel{if_io_tqg_1}
>>> 100082 root -76 - 0K   272K -       0 297.7H  95.20% kernel{if_io_tqg_0}
>>>
>>>  And it is new to me.
>>
>> I'm sure you will get it solved more quick if you perform bisection of revision
>> even though it will take time.
>  I'll try latest version (seems here were a lot of commit to iflib after
> my revision) and after that try yo bisect.
>
> --
> // Lev Serebryakov
>