From: Bruce Richardson <bruce.richardson@intel.com>
To: Panu Matilainen <pmatilai@redhat.com>
Cc: Ferruh Yigit <ferruh.yigit@intel.com>,
dev@dpdk.org, David Marchand <david.marchand@6wind.com>,
Helin Zhang <helin.zhang@intel.com>
Subject: Re: [dpdk-dev] [PATCH v3 0/2] slow data path communication between DPDK port and Linux
Date: Wed, 16 Mar 2016 11:07:41 +0000 [thread overview]
Message-ID: <20160316110740.GA24668@bricha3-MOBL3> (raw)
In-Reply-To: <56E917AD.2060701@redhat.com>
On Wed, Mar 16, 2016 at 10:22:05AM +0200, Panu Matilainen wrote:
> On 03/16/2016 10:19 AM, Ferruh Yigit wrote:
> >On 3/16/2016 7:26 AM, Panu Matilainen wrote:
> >>On 03/14/2016 05:32 PM, Ferruh Yigit wrote:
> >>>On 3/9/2016 11:17 AM, Ferruh Yigit wrote:
> >>>>This patch sent to keep record of latest status of the work.
> >>>>
> >>>>
> >>>>This is slow data path communication implementation based on existing KNI.
> >>>>
> >>>>Difference is: librte_kni converted into a PMD, kdp kernel module is almost
> >>>>same except all control path functionality removed and some simplification done.
> >>>>
> >>>>Motivation is to simplify slow path data communication.
> >>>>Now any application can use this new PMD to send/get data to Linux kernel.
> >>>>
> >>>>PMD supports two communication methods:
> >>>>
> >>>>1) KDP kernel module
> >>>>PMD initialization functions handles creating virtual interfaces (with help of
> >>>>kdp kernel module) and created FIFO. FIFO is used to share data between
> >>>>userspace and kernelspace. This is default method.
> >>>>
> >>>>2) tun/tap module
> >>>>When KDP module is not inserted, PMD creates tap interface and transfers
> >>>>packets using tap interface.
> >>>>
> >>>>In long term this patch intends to replace the KNI and KNI will be
> >>>>depreciated.
> >>>>
> >>>
> >>>Self-NACK: Will work on another option that does not introduce new
> >>>kernel module.
> >>>
> >>
> >>Hmm, care to elaborate a bit? The second mode of this PMD already was
> >>free of external kernel modules. Do you mean you'll be just removing
> >>mode 1) from the PMD or looking at something completely different?
> >>
> >>Just thinking that tun/tap PMD sounds like a useful thing to have, I
> >>hope you're not abandoning that.
> >>
> >
> >It will be KNI PMD.
> >Plan is to have something like KDP, but with existing KNI kernel module.
> >There will be tun/tap support as fallback.
>
> Hum, now I'm confused. I was under the impression everybody hated KNI and
> wanted to get rid of it, and certainly not build future solutions on top of
> it?
>
KNI has it's issues - mainly: a) not being upstream and b) having large
amounts of code to do port management in it, that is best handled by other
means - but the code for transferring packets between kernel space and userspace
is more performant and scalable than TUN/TAP, so we need to keep that around
unless/until we can get TUN/TAP to reach the same performance levels.
Now, we are thinking of some ways in which that can be achieved, but any such
solution is going to be a bit out, so making any driver for transferring packets
from user->kernel and vice versa might as well take advantage of KNI as well as
TUN/TAP so as to allow those who want the extra performance to have it.
Regards,
/Bruce
prev parent reply other threads:[~2016-03-16 11:07 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-27 16:32 [dpdk-dev] [PATCH " Ferruh Yigit
2016-01-27 16:32 ` [dpdk-dev] [PATCH 1/2] kdp: add kernel data path kernel module Ferruh Yigit
2016-02-08 17:14 ` Reshma Pattan
2016-02-09 10:53 ` Ferruh Yigit
2016-01-27 16:32 ` [dpdk-dev] [PATCH 2/2] kdp: add virtual PMD for kernel slow data path communication Ferruh Yigit
2016-01-28 8:16 ` Xu, Qian Q
2016-01-29 16:04 ` Yigit, Ferruh
2016-02-09 17:33 ` Reshma Pattan
2016-02-09 17:51 ` Ferruh Yigit
2016-02-19 5:05 ` [dpdk-dev] [PATCH v2 0/2] slow data path communication between DPDK port and Linux Ferruh Yigit
2016-02-19 5:05 ` [dpdk-dev] [PATCH v2 1/2] kdp: add kernel data path kernel module Ferruh Yigit
2016-02-19 5:05 ` [dpdk-dev] [PATCH v2 2/2] kdp: add virtual PMD for kernel slow data path communication Ferruh Yigit
2016-03-09 11:17 ` [dpdk-dev] [PATCH v3 0/2] slow data path communication between DPDK port and Linux Ferruh Yigit
2016-03-09 11:17 ` [dpdk-dev] [PATCH v3 1/2] kdp: add kernel data path kernel module Ferruh Yigit
2016-03-09 11:17 ` [dpdk-dev] [PATCH v3 2/2] kdp: add virtual PMD for kernel slow data path communication Ferruh Yigit
2016-03-14 15:32 ` [dpdk-dev] [PATCH v3 0/2] slow data path communication between DPDK port and Linux Ferruh Yigit
2016-03-16 7:26 ` Panu Matilainen
2016-03-16 8:19 ` Ferruh Yigit
2016-03-16 8:22 ` Panu Matilainen
2016-03-16 10:26 ` Ferruh Yigit
2016-03-16 10:45 ` Thomas Monjalon
2016-03-16 11:07 ` Mcnamara, John
2016-03-16 11:13 ` Ferruh Yigit
2016-03-16 13:23 ` Panu Matilainen
2016-03-16 13:15 ` Panu Matilainen
2016-03-16 13:58 ` Thomas Monjalon
2016-03-16 15:03 ` Panu Matilainen
2016-03-16 15:15 ` Thomas Monjalon
2016-03-16 11:07 ` Bruce Richardson [this message]
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