[dpdk-dev] Fast Path Query

[Deepak Sehrawat]

Hi Helin,

If we use exception_path or KNI, which extracts packet from Linux kernel
(for DPDK application processing), will it still remain fast path? Will it
not impact the performance; as Linux interrupt framework shall also come
into picture here?


On Wed, Jan 14, 2015 at 1:17 PM, Zhang, Helin <helin.zhang at intel.com> wrote:

> Hi Deepak
>
> If a NIC port is controlled by DPDK, all packets received by that port
> will go directly to DPDK, and Linux kernel doesn't know those packets
> anymore.
> But, the packets received by DPDK can be put into kernel by two special
> ways. They are exception_path and KNI. Please check the examples/ for more
> details.
> In the future, a port may be co-controlled by both Linux and DPDK. Part of
> queues will be controlled by Linux kernel driver, part of queues will be
> controlled by DPDK. Check the DPDK roadmap for more details.
>
> Regards,
> Helin
>
> > -----Original Message-----
> > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Deepak Sehrawat
> > Sent: Wednesday, January 14, 2015 2:16 PM
> > To: dev at dpdk.org
> > Subject: [dpdk-dev] Fast Path Query
> >
> > Hi All,
> >
> > I have a use-case where my slow path application (control path) is to
> run on
> > Linux where as my data path is to run as DPDK application. Because both
> > control and data packets are going to be received via same NIC card, how
> will
> > these two flows be separated and passed on to Linux control app and DPDK
> > data path app respectively? In short I want to understand how NIC
> received
> > packets are separated between Linux Eth driver and PMD (poll mode
> > driver) of DPDK?
> >
> > Thanks for the help in advance.
> >
> > Thanks,
> > Deepak
>



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DEEPAK $EHRAWAT
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Hughes Systique Corporation,
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deepak.sehrawat at hsc.com
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