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From: Thomas Monjalon <thomas.monjalon@6wind.com>
To: "Lu, Wenzhuo" <wenzhuo.lu@intel.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v3] ethdev: fix DCB config issue on ixgbe
Date: Thu, 23 Jun 2016 14:21:48 +0200	[thread overview]
Message-ID: <3037324.FL8zRspYFl@xps13> (raw)
In-Reply-To: <6A0DE07E22DDAD4C9103DF62FEBC090903489DBD@shsmsx102.ccr.corp.intel.com>

2016-06-23 01:04, Lu, Wenzhuo:
> From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com]
> > 2016-05-06 05:33, Wenzhuo Lu:
> > > +int
> > > +rte_eth_dev_mq_mode_set(uint8_t port_id,
> > > +			enum rte_eth_rx_mq_mode rx_mq_mode,
> > > +			enum rte_eth_tx_mq_mode tx_mq_mode);
> > 
> > I've really tried to think about it and I think it is more or less a hack.
> > First, it is not explained in the doc when we should use
> > rte_eth_dev_mq_mode_set() instead of a simple call to rte_eth_dev_configure().
> > Second, I don't understand why having a function which configures the
> > "multiqueue modes" without configuring properly RSS/VMDq/DCB.
> > Last, it is said that rte_eth_dev_configure() "must be invoked first before any
> > other function in the Ethernet API".
> Sorry, didn't notice this announcement.
> 
> > My opinion is that the primary goal of rte_eth_dev_configure() was "Embedding
> > all configuration information in a single data structure"
> > but it is currently configuring only speed and some flow steering (only RSS,
> > VMDq, DCB and flow director).
> > This bug and the state of the ethdev API clearly shows that we must have one
> > function per feature (or group of features) and drop rte_eth_dev_configure().
> > 
> > You can argue it is a just a personal feeling and this comment comes late, but I
> > promise it is not easy to give a negative opinion because of design perspective.
> > I strongly feel we must stop workarounding the ethdev API issues and start really
> > fixing it.
> > 
> > Hope you understand and agree to work on a new API.
> I have the same feeling with you. There's some problem with rte_eth_dev_configure. So this patch is a workaround more than a real fix.
> But the problem is this API has already been used. What I think is could we take this workaround as a first step. It need not ask the APP to change too much.
> Then we can discuss how could we rework on a new API or APIs. We all know the change in rte layer is not easy and need to be very careful :)

We probably need more opinions.
I think it is not a good idea to introduce a new API only to workaround
another one and keep confusion in place.
A similar approach which looks better is to introduce a new API which will
partly replace the old one and will remain a good one when the old API
will be completely removed.
In other words, we should introduce a good API for flow steering as soon
as possible and deprecate rte_eth_dev_configure().

  reply	other threads:[~2016-06-23 12:21 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-11  8:24 [dpdk-dev] [PATCH] lib: " Wenzhuo Lu
2016-04-11  9:52 ` Thomas Monjalon
2016-04-12  0:39   ` Lu, Wenzhuo
2016-05-04 21:47 ` [dpdk-dev] [PATCH v2] " Wenzhuo Lu
2016-05-05 21:33 ` [dpdk-dev] [PATCH v3] ethdev: " Wenzhuo Lu
2016-06-17 11:21   ` De Lara Guarch, Pablo
2016-06-22 17:01   ` Thomas Monjalon
2016-06-23  1:04     ` Lu, Wenzhuo
2016-06-23 12:21       ` Thomas Monjalon [this message]
2016-06-24  0:45         ` Lu, Wenzhuo
2016-06-30  1:40           ` Lu, Wenzhuo
2016-06-30  7:41             ` Thomas Monjalon
2016-06-30  8:23               ` Lu, Wenzhuo
2016-06-30  8:47               ` Lu, Wenzhuo

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