Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 29 Aug 2012 11:17:09 +0400
From:      Andrey Zonov <zont@FreeBSD.org>
To:        lev@freebsd.org
Cc:        freebsd-current@freebsd.org
Subject:   Re: What is "Fast task queue"? (Was: How to understand what `swi5' kernel thread does?)
Message-ID:  <503DC1F5.1070207@FreeBSD.org>
In-Reply-To: <201208280744.23419.jhb@freebsd.org>
References:  <135297243.20120827061957@serebryakov.spb.ru> <201208271226.03496.jhb@freebsd.org> <1758728845.20120828004713@serebryakov.spb.ru> <201208280744.23419.jhb@freebsd.org>

next in thread | previous in thread | raw e-mail | index | archive | help
This is an OpenPGP/MIME signed message (RFC 2440 and 3156)
--------------enig1E23293266A64FE0BE234018
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

On 8/28/12 3:44 PM, John Baldwin wrote:
> On Monday, August 27, 2012 4:47:13 pm Lev Serebryakov wrote:
>> Hello, John.
>> You wrote 27 =D0=B0=D0=B2=D0=B3=D1=83=D1=81=D1=82=D0=B0 2012 =D0=B3., =
20:26:03:
>>
>>>>  What "fast tasks" are performed via this queue? Under network load =
it
>>>> is main consumer of CPU.
>> JB> Certain NIC drivers perform much of their interrupt handling in th=
at=20
> thread.
>>   Yep,  I've found, that my if_vr uses it. One more question: does ipf=
w
>>  rules works in same thread? I have ``net.isr.dispatch=3D"direct"'' se=
t.
>=20
> Yes, with the default setting of direct dispatch, all of the receive
> side of the network stack runs in the driver's interrupt handler.  In
> the case of vr(4) that would be in this thread.
>=20

Lev,

If you have more than one CPU, you can try this patch [1].  It adds
flowid in mbufs and makes possible to use multiple netisr threads.
Apply the patch and put in your loader.conf the following:

net.isr.maxthreads=3D$ncpu (2, 4 or whatever you want)
net.isr.dispatch=3Ddeferred

PS: original patch was written by melifaro.

[1] http://people.freebsd.org/~zont/netisr.patch

--=20
Andrey Zonov


--------------enig1E23293266A64FE0BE234018
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: OpenPGP digital signature
Content-Disposition: attachment; filename="signature.asc"

-----BEGIN PGP SIGNATURE-----
Version: GnuPG/MacGPG2 v2.0.18 (Darwin)
Comment: GPGTools - http://gpgtools.org

iQEcBAEBAgAGBQJQPcH5AAoJEBWLemxX/CvTcdoH+QFHz7eOQCBkSiaRXJrH38ey
giyG+VuW9V5/O8Q4u05hyUbq/af67O1NELiGviXu4mjo+yO7egDBp34LfMIKNtW6
onzMYsS2IYML2518q3TlMfRZu3raQT+/kXJStosAfU3sJUSAS/FO2wIF77Uimeut
48jfh3tTB66VfMu2k9gCMGIVEKL4TnTbfMKG5VkHS/I1EBJcdwYlPSGB3C6ef3qG
Yx5AO2KM+ow6MH1k88cT5kpJM4qNUUv83C2FPnWlUAWEVCWednn9lAy9optMqtWj
vlY/fBLBcPk7/oFkkhlusuhx+l+d+SmZ5GX0vosipzLcHR/u7s0unDOZ3T4L1Wg=
=0g6c
-----END PGP SIGNATURE-----

--------------enig1E23293266A64FE0BE234018--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?503DC1F5.1070207>