DPDK patches and discussions
 help / color / mirror / Atom feed
From: Ori Kam <orika@nvidia.com>
To: Jerin Jacob <jerinjacobk@gmail.com>,
	Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Cc: Ivan Malov <ivan.malov@arknetworks.am>,
	"NBU-Contact-Thomas Monjalon (EXTERNAL)" <thomas@monjalon.net>,
	Ivan Malov <ivan.malov@oktetlabs.ru>,
	Ferruh Yigit <ferruh.yigit@amd.com>,
	Nithin Kumar Dabilpuram <ndabilpuram@marvell.com>,
	Aman Singh <aman.deep.singh@intel.com>,
	Yuying Zhang <yuying.zhang@intel.com>,
	"dev@dpdk.org" <dev@dpdk.org>,
	Hanumanth Reddy Pothula <hpothula@marvell.com>,
	Slava Ovsiienko <viacheslavo@nvidia.com>,
	Jerin Jacob Kollanukkaran <jerinj@marvell.com>,
	"david.marchand@redhat.com" <david.marchand@redhat.com>
Subject: RE: [EXT] Re: [PATCH v5 2/2] app/testpmd: add command to process Rx metadata negotiation
Date: Wed, 1 Feb 2023 09:00:34 +0000	[thread overview]
Message-ID: <MW2PR12MB4666D916B9F9BBD8C1DA3A77D6D19@MW2PR12MB4666.namprd12.prod.outlook.com> (raw)
In-Reply-To: <CALBAE1PDCnavrMutKqQuOQiz4dUweyqst+BcuuNQQE=NCmMV8A@mail.gmail.com>

Hi all,

Sorry for jumping in late,

> -----Original Message-----
> From: Jerin Jacob <jerinjacobk@gmail.com>
> Sent: Wednesday, 1 February 2023 10:53
> 
> On Wed, Feb 1, 2023 at 12:46 PM Andrew Rybchenko
> <andrew.rybchenko@oktetlabs.ru> wrote:
> >
> > On 2/1/23 09:10, Ivan Malov wrote:
> > > Hello everyone,
> > >
> > > Since making automatic, or implicit, offload decisions does
> > > not belong in testpmd responsibility domain, it should be
> > > safer to avoid calling the "negotiate metadata delivery"
> > > API with some default selection unless the user asks to
> > > do so explicitly, via internal CLI or app options.
> > >
> > > With that in mind, port config <port_id> ... sounds OK.
> > >
> > > PMDs that support flow primitives which can generate metadata
> > > but, if in started state, can't enable its delivery may pass
> > > appropriate rte_error messages to the user suggesting
> > > they enable delivery of such metadata from NIC to PMD
> > > first. This way, if the person operating testpmd
> > > enters a flow create command and that fails,
> > > they can figure out the inconsistency, stop
> > > the port, negotiate, start and try again.
> > >
> > > As for non-debug applications, their developers shall
> > > be properly informed about the problem of enabling
> > > delivery of metadata from NIC to PMD. This way,
> > > they will invoke the negotiate API by default
> > > in their apps, with the feature selection (eg.
> > > MARK) as per nature of the app's business.
> > >
> > > This API should indeed be helpful to some PMDs with
> > > regard to collecting upfront knowledge like this.
> > > At the same time, should be benign to those PMDs
> > > who do not need this knowledge and can enable
> > > delivery of metadata right when inserting the
> > > flow rules. So I hope the API does not create
> > > too much discomfort to vendors not needing it.
> > >
> > > Thank you.
> > >
> > > On Wed, 1 Feb 2023, Thomas Monjalon wrote:
> > >
> > >> 31/01/2023 17:17, Jerin Jacob:
> > >>> On Fri, Jan 27, 2023 at 8:31 PM Thomas Monjalon
> <thomas@monjalon.net>
> > >>> wrote:
> > >>>>
> > >>>> 27/01/2023 11:42, Nithin Kumar Dabilpuram:
> > >>>>> From: Thomas Monjalon <thomas@monjalon.net>
> > >>>>>> 27/01/2023 06:02, Nithin Kumar Dabilpuram:
> > >>>>>>> From: Thomas Monjalon <thomas@monjalon.net>
> > >>>>>>>> Ferruh is proposing to have a command "port config <port_id>
> ..."
> > >>>>>>>> to configure the flags to negotiate.
> > >>>>>>>> Are you OK with this approach?
> > >>>>>>>
> > >>>>>>> Yes, we are fine to have such command to enable and disable the
> > >>>>>>> feature
> > >>>>>>> with default being it disabled if supported by PMD.
> > >>>>>>> Is default being disabled fine if the feature is supported by a
> > >>>>>>> PMD ?
> > >>>>>>
> > >>>>>> I think the default should be enabled for ease of use.
> > >>>>>
> > >>>>> Since testpmd is used extensively for benchmarking purposes, we
> > >>>>> thought it should have minimum features
> > >>>>> enabled by default. The default testpmd doesn't have any Rx/Tx
> > >>>>> offloads enabled(except for FAST FREE),  default
> > >>>>> fwd mode being "iofwd" and the Rx metadata is only referenced
> when
> > >>>>> dumping packets.
> > >>>>>
> > >>>>>
> > >>>>>> Do we have similar features disables by default?
> > >>>>>> I mean do we know features in testpmd which require a "double
> > >>>>>> enablement"
> > >>>>>> like one configuration command + one rte_flow rule?
> > >>>>>
> > >>>>> Spec itself is that way i.e "RTE_FLOW_RULE +
> > >>>>> RX_METADATA_NEGOTIATE(once)"
> > >>>>>
> > >>>>> Isn't it enough if
> > >>>>>
> > >>>>> #1 We have enough print when rte_flow is being create without
> > >>>>> negotiation done and ask user to enable rx metadata using
> > >>>>> "port config <port_id>..."
> > >>>>> #2 Provide testpmd app arg to enable Rx metadata(for example "
> > >>>>> --rx-metadata") like other features to avoid calling another
> > >>>>> command before rte flow create.
> > >>>>
> > >>>> I'm not sure what is best.
> > >>>> I will let others discuss this part.
> > >>>
> > >>> IMO, enabling something always defeat the purpose to negotiate. IMO,
> > >>> someone needs to negotiate
> > >>> for a feature if the feature is needed. I think, the double enablement
> > >>> is part of the spec itself. In case, The PMD
> > >>> drivers won't like double enablement, no need to implement the PMD
> > >>> callback. That way, there is no change in the existing flow.
> > >>>
> > >>> The reason why cnxk driver thought of leveraging negotiate() feature
> > >>> so that it helps for optimization. e.s.p
> > >>> function template for multiprocess case as we know what features
> > >>> needed in fastpath upfront.
> > >>>
> > >>> If there still concerns with patch we can take up this to TB decide
> > >>> one way or another to make forward progress. Let us know.
> > >>
> > >> Ferruh, Andrew, Ori, Ivan, what is your opinion?
> > >> Let's progress with this patch to make it in -rc1.
> >
> > As I understand all agreed that we need testpmd command to
> > control negotiated Rx metadata. May be even command-line
> > option would be useful.
> >
> > So, remaining question is what should be the default value in
> > testpmd. Note that it is just testpmd question since default
> > value in an abstract application is nothing negotiated
> > (if I'm not mistaken).
> >
> > The key advantaan ge of the current behaviour is to avoid
> > "double-enabling" in testpmd. It preserves behaviour which
> > we had before before the API addition. It is a strong
> > argument. Basically it puts the feature into the same
> > basket as FAST_FREE - need an action to run faster.
> 
> I think, there is a disconnect here. FAST_FREE is enabled by default.
> i.e We don't need any specific action to run faster. To align with performance
> test application, by default the configuration should be run faster. User
> needs to give explicit configuration to allow more offload or the one causes
> the mpps drops. IMO, That is the theme followed in testpmd.
> 
> 
I agree with Andrew, the default should stay the same, as now, PMD may already implement
logic to only enable the feature if there is a flow rule.
Changing the default will result in breaking applications.

I want to suggest new approach for this feature, 
maybe we can use the rte_flow_configure, and add a new bit that says if those
actions are going to be used.
What do you think?



> > I see no problem in such approach.
> >
> > The key disadvantage is the difference in testpmd and
> > other applications default behaviour.
> >
> > I'd look at the feature in the following way:
> > if an application theoretically wants to use
> > USER_FLAG, USER_MARK or TUNNEL_ID it must negotiate
> > corresponding Rx metadata to ensure that the feature is
> > available and HW is informed that application may need it.
> > Since testpmd supports corresponding flow API actions and
> > flow tunnels, it tries to negotiate it by default, but do
> > not fail if the negotiation fails.
> >
> > So, I'd would vote to keeping the default value as is.
> >

  reply	other threads:[~2023-02-01  9:00 UTC|newest]

Thread overview: 73+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-01  4:41 [PATCH] app/testpmd: add command line argument 'rx-metadata' Hanumanth Pothula
2022-08-01 13:11 ` Hanumanth Pothula
2022-08-01 13:13 ` Hanumanth Pothula
2022-08-01 19:41   ` Ivan Malov
2022-08-02 16:45   ` [PATCH] app/testpmd: add command line argument 'nic-to-pmd-rx-metadata' Hanumanth Pothula
2022-08-02 16:45     ` [PATCH v2 1/2] version: 22.11-rc0 Hanumanth Pothula
2022-08-02 16:45     ` [PATCH v2 2/2] app/testpmd: add command line argument 'nic-to-pmd-rx-metadata' Hanumanth Pothula
2022-08-02 17:51   ` [PATCH v2 1/1] " Hanumanth Pothula
2022-08-30 12:36     ` Hanumanth Reddy Pothula
2022-09-01  8:03     ` Singh, Aman Deep
2022-10-04 14:48       ` Andrew Rybchenko
2022-10-06 18:35     ` [PATCH v3 1/1] app/testpmd: control passing Rx metadata to PMD Hanumanth Pothula
2022-10-17  8:32       ` Andrew Rybchenko
2022-10-27  7:34         ` Thomas Monjalon
2022-10-27 12:54           ` Thomas Monjalon
2022-12-02 16:14             ` [EXT] " Hanumanth Reddy Pothula
2022-12-02 19:41               ` Thomas Monjalon
2022-12-05  7:59                 ` Hanumanth Reddy Pothula
2022-12-05  8:28                   ` Thomas Monjalon
2022-12-05  9:43                     ` Slava Ovsiienko
2022-12-20 20:02       ` [PATCH v4 1/2] ethdev: control Rx metadata negotiation Hanumanth Pothula
2022-12-20 20:02         ` [PATCH v4 2/2] app/testpmd: add command to process " Hanumanth Pothula
2022-12-20 21:23           ` Stephen Hemminger
2022-12-21  2:07         ` [PATCH v5 1/2] ethdev: fix ethdev configuration state on reset Hanumanth Pothula
2022-12-21  2:07           ` [PATCH v5 2/2] app/testpmd: add command to process Rx metadata negotiation Hanumanth Pothula
2023-01-18 10:32             ` Thomas Monjalon
2023-01-19 10:33               ` [EXT] " Hanumanth Reddy Pothula
2023-01-25 12:51                 ` Thomas Monjalon
2023-01-24 18:04             ` Ferruh Yigit
2023-01-25  9:30               ` [EXT] " Hanumanth Reddy Pothula
2023-01-25 12:55                 ` Thomas Monjalon
2023-01-25 13:55                   ` Ferruh Yigit
2023-01-25 13:59                     ` Thomas Monjalon
2023-01-25 14:42                       ` Nithin Kumar Dabilpuram
2023-01-26 11:03                         ` Thomas Monjalon
2023-01-27  5:02                           ` Nithin Kumar Dabilpuram
2023-01-27  8:54                             ` Thomas Monjalon
2023-01-27 10:42                               ` Nithin Kumar Dabilpuram
2023-01-27 15:01                                 ` Thomas Monjalon
2023-01-31 16:17                                   ` Jerin Jacob
2023-01-31 23:03                                     ` Thomas Monjalon
2023-02-01  6:10                                       ` Ivan Malov
2023-02-01  7:16                                         ` Andrew Rybchenko
2023-02-01  8:53                                           ` Jerin Jacob
2023-02-01  9:00                                             ` Ori Kam [this message]
2023-02-01  9:05                                               ` Thomas Monjalon
2023-02-01  9:07                                                 ` Andrew Rybchenko
2023-02-01  9:14                                                   ` Jerin Jacob
2023-02-01  9:29                                                     ` Andrew Rybchenko
2023-02-01 10:48                                                       ` Jerin Jacob
2023-02-01 10:58                                                         ` Andrew Rybchenko
2023-02-01 11:04                                                           ` Thomas Monjalon
2023-02-01 11:15                                                             ` Jerin Jacob
2023-02-01 11:35                                                               ` Ferruh Yigit
2023-02-01 13:48                                                                 ` Jerin Jacob
2023-02-01 14:50                                                                   ` Ferruh Yigit
2023-02-01 15:22                                                                     ` Jerin Jacob
2023-02-02  8:43                                                                       ` Ferruh Yigit
2023-02-02  8:50                                                                         ` Ivan Malov
2023-02-02  9:17                                                                           ` Ferruh Yigit
2023-02-02 10:41                                                                             ` Ivan Malov
2023-02-02 10:48                                                                               ` Ivan Malov
2023-02-02 11:41                                                                                 ` Thomas Monjalon
2023-02-02 11:55                                                                                   ` Ivan Malov
2023-02-02 12:03                                                                                     ` Thomas Monjalon
2023-02-02 12:21                                                                                       ` Andrew Rybchenko
2023-02-01 11:20                                                             ` Ivan Malov
2023-01-25 13:17                 ` Ferruh Yigit
2023-01-25 13:21                   ` Ferruh Yigit
2023-01-25 13:21                 ` Ferruh Yigit
2023-01-16 10:43           ` [PATCH v5 1/2] ethdev: fix ethdev configuration state on reset Hanumanth Reddy Pothula
2023-01-18 10:29           ` Thomas Monjalon
2023-01-24 18:14             ` Ferruh Yigit

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=MW2PR12MB4666D916B9F9BBD8C1DA3A77D6D19@MW2PR12MB4666.namprd12.prod.outlook.com \
    --to=orika@nvidia.com \
    --cc=aman.deep.singh@intel.com \
    --cc=andrew.rybchenko@oktetlabs.ru \
    --cc=david.marchand@redhat.com \
    --cc=dev@dpdk.org \
    --cc=ferruh.yigit@amd.com \
    --cc=hpothula@marvell.com \
    --cc=ivan.malov@arknetworks.am \
    --cc=ivan.malov@oktetlabs.ru \
    --cc=jerinj@marvell.com \
    --cc=jerinjacobk@gmail.com \
    --cc=ndabilpuram@marvell.com \
    --cc=thomas@monjalon.net \
    --cc=viacheslavo@nvidia.com \
    --cc=yuying.zhang@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).