From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Richardson, Bruce" Subject: Re: [PATCH v2 07/11 1/2] vdev: new registration API Date: Fri, 11 Apr 2014 20:08:10 +0000 Message-ID: <59AF69C657FD0841A61C55336867B5B01A9FC02F@IRSMSX103.ger.corp.intel.com> References: <1460632.jOzC6OEr8u@xps13> <8367341.P2CbmhJR7D@xps13> <20140411155000.GD911@hmsreliant.think-freely.org> <4074308.XK7oTvuRSP@xps13> <20140411174454.GE911@hmsreliant.think-freely.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Cc: "dev-VfR2kkLFssw@public.gmane.org" To: Neil Horman , Thomas Monjalon Return-path: In-Reply-To: <20140411174454.GE911-B26myB8xz7F8NnZeBjwnZQMhkBWG/bsMQH7oEaQurus@public.gmane.org> Content-Language: en-US List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" > -----Original Message----- > From: dev [mailto:dev-bounces-VfR2kkLFssw@public.gmane.org] On Behalf Of Neil Horman > Sent: Friday, April 11, 2014 6:45 PM > To: Thomas Monjalon > Cc: dev-VfR2kkLFssw@public.gmane.org > Subject: Re: [dpdk-dev] [PATCH v2 07/11 1/2] vdev: new registration API >=20 > On Fri, Apr 11, 2014 at 06:18:08PM +0200, Thomas Monjalon wrote: > > 2014-04-11 11:50, Neil Horman: > > > > It seems that your patch is not removing > > rte_eth_ring_pair_create/rte_eth_ring_pair_attach so I'm not sure you > > can dynamically change the PMD in this case. > > > Ew, I had missed those calls. Yes, those should be encapsulated as some = driver > ops or some such. I'll look at that when I rebase. Regardless however, = I didn't > mean to state that pmds could be switched while running, only that the pm= d to > use could be specified at run time. Though, you're correct, pmd_ring doe= sn't > seem to hold in line with the other pmds in their isolation. >=20 The ring PMD is probably best treated separately from the other PMDs as it'= s not really a device poll-mode driver. Instead, it's a general library tha= t presents an API to make a ring, or set of rings, appear as a poll-mode dr= iver ethdev. The EAL command to have one created at startup time was just a= n addon after-the-fact in case someone might find it useful :-). However, i= t's primary purpose was to allow applications to be written which could use= physical NICs or rings interchangeably. For example, an app with multiple = stages in a pipeline, where each stage just reads from an ethdev without ca= ring if it's actually reading from a port or from packets sent from another= lcore/function etc. Another example might be where an application wishes t= o sometimes loop packets back to itself, in this case it uses the C API to = create an additional ring ethdev which it uses as output port for any packe= ts it wants looped back - no special handling needed, everything is an ethd= ev to it on which it calls rx_burst or tx_burst. It's also likely that in f= uture we will develop other libraries which wish to present their functiona= lity via rx_burst/tx_burst functions i.e. as an ethdev. Regards, /Bruce