Date: Mon, 3 Feb 2020 14:39:03 -0800 From: Navdeep Parhar <np@FreeBSD.org> To: Slawa Olhovchenkov <slw@zxy.spb.ru> Cc: freebsd-net@freebsd.org Subject: Re: Chelsio NETMAP performance Message-ID: <6868f207-d054-3d45-b60d-eaf7115760c1@FreeBSD.org> In-Reply-To: <20200203222321.GB8012@zxy.spb.ru> References: <20200203201728.GC8028@zxy.spb.ru> <863de9e1-42cc-6f3a-5c1f-1bf737714c9f@FreeBSD.org> <20200203222321.GB8012@zxy.spb.ru>
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On 2/3/20 2:23 PM, Slawa Olhovchenkov wrote:
> On Mon, Feb 03, 2020 at 01:39:52PM -0800, Navdeep Parhar wrote:
>=20
>> On 2/3/20 12:17 PM, Slawa Olhovchenkov wrote:
>>> I am try to use Chelsio T540-CR in netmap mode and see poor (compared=
>>> to Intel 82599ES) performance.
>>
>> What approximate FreeBSD version is this?
>=20
> 12.1-STABLE
>=20
>>>
>>> Same application ac receive only about 8.9Mpss, compared to 12.5Mpps
>>> at Intel.
>>>
>>> pmc profile show mostly time spend in:
>>>
>>> 49.76% [17802] service_nm_rxq @ /boot/kernel/if_cxgbe.ko
>>> 100.0% [17802] t4_vi_intr
>>> 100.0% [17802] ithread_loop @ /boot/kernel/kernel
>>> 100.0% [17802] fork_exit
>>>
>>>
>>> to be exact at line
>>>
>>> while ((d->rsp.u.type_gen & F_RSPD_GEN) =3D=3D nm_rxq->iq_gen=
) {
>>>
>>> Is this maximum limit for this vendor?
>>
>> No, a T540 should be able to sink full 10Gbps (14.88Mpps) on a single =
rx
>> queue. Try adding this to your loader.conf:
>>
>> hw.cxgbe.toecaps_allowed=3D"0"
>>
>> Then try simple netmap "pkt-gen -f rx" instead of any custom app and s=
ee
>> how many pps it's able to sink.
>=20
> Thanks! `hw.cxgbe.toecaps_allowed=3D"0"` allow recive 14Mpps for may
> application too!
>=20
> Now I am got only 10% less performance compared to Intel, as I see by
> higher Chelsio interrupt cpu time (top show about 30% for every
> interrupt handler). Is this normal? Is this posible to optimize?
Try changing the interrupt holdoff timer for the netmap rx queues.
This shows the list of timers available (in microseconds):
# sysctl dev.t5nex.0.holdoff_timers
nm_holdoff_tmr_idx is a 0-based index into the list above. So if the
tmr idx is 0 you are using the 0th (first) value from the list of
timers. Try increasing nm_holdoff_tmr_idx and see if that brings down
the interrupt rate under control.
# sysctl hw.cxgbe.nm_holdoff_tmr_idx=3D3/4/5
Regards,
Navdeep
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