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From: "Zhou, Danny" <danny.zhou@intel.com>
To: Stephen Hemminger <stephen@networkplumber.org>, "Michael  Marchetti"
 <mmarchetti@sandvine.com>
Thread-Topic: [dpdk-dev] overcommitting CPUs
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Date: Tue, 26 Aug 2014 16:59:14 +0000
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Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] overcommitting CPUs
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> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Stephen Hemminger
> Sent: Wednesday, August 27, 2014 12:39 AM
> To: Michael Marchetti
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] overcommitting CPUs
>=20
> On Tue, 26 Aug 2014 16:27:14 +0000
> "Michael  Marchetti" <mmarchetti@sandvine.com> wrote:
>=20
> > Hi, has there been any consideration to introduce a non-spinning networ=
k driver (interrupt based), for the purpose of overcommitting
> CPUs in a virtualized environment?  This would obviously have reduced hig=
h-end performance but would allow for increased guest
> density (sharing of physical CPUs) on a host.
> >
> > I am interested in adding support for this kind of operation, is there =
any interest in the community?
> >
> > Thanks,
> >
> > Mike.
>=20
> Better to implement a NAPI like algorithm that adapts from poll to interr=
upt.

Agreed, but DPDK is currently pure poll-mode based, so unlike the NAPI' sim=
ple algorithm, the new heuristic algorithm should not switch from poll-mode=
 to interrupt-mode immediately once there is no packet in the recent poll. =
Otherwise, mode switching will be too frequent which brings serious negativ=
e performance impact to DPDK.