DPDK patches and discussions
 help / color / mirror / Atom feed
From: Thomas Monjalon <thomas@monjalon.net>
To: Ferruh Yigit <ferruh.yigit@intel.com>
Cc: Asaf Penso <asafp@nvidia.com>, "dev@dpdk.org" <dev@dpdk.org>,
	"Gal Cohen (ProdM)" <galco@nvidia.com>,
	Andrew Rybchenko <arybchenko@solarflare.com>,
	ajit.khaparde@broadcom.com, jerinj@marvell.com
Subject: Re: [dpdk-dev] [PATCH v4] doc: add new tables for rte flow items and actions support
Date: Wed, 17 Feb 2021 11:49:08 +0100
Message-ID: <24451137.kzuPNkPQvE@thomas> (raw)
In-Reply-To: <6c467b94-8a0e-91b3-4c4f-576730a7ed33@intel.com>

17/02/2021 11:37, Ferruh Yigit:
> On 2/17/2021 5:57 AM, Asaf Penso wrote:
> > From: Ferruh Yigit <ferruh.yigit@intel.com>
> >> On 2/7/2021 10:52 AM, Asaf Penso wrote:
> >>> In http://doc.dpdk.org/guides/nics/overview.html, table 1.1 lists all
> >>> supported features.
> >>> It has a single line for "Flow API" that refers to rte_flow support.
> >>> rte_flow is composed of many items and actions that are not expressed
> >>> in this single line.
> >>>
> >>> The following new tables are suggested:
> >>> 1. rte_flow items
> >>> 2. rte_flow actions
> >>>
> >>
> >> Hi Asaf,
> >>
> >> I understand the intention, but I am not sure about this.
> >>
> >> The Flow API does not provide a capability or feature list in the API level, by
> >> design, because it is very hard to do it correct, but this patch tries to do it in the
> >> documentation level.
> >>
> >> This will be missing lots of details, the flow items and actions documented as
> >> supported may and may not be supported based on the details.
> >>
> > 
> > Which missing details are you referring to? All flow items and all actions are listed.
> > 
> 
> Patterns are complex, any rule can be valid or invalid based on provided pattern 
> values (details), also any rule can be valid or invalid based on previous rules 
> or configuration.
> 
> In practice this information is much more useful if it is provided by API, but 
> we are not able to do it because of its complex nature, it should be same level 
> of complexity to provide this information by documentation.
> 
> >> It will be very hard to read this table (when it becomes full), also will be very hard
> >> to maintain.
> > 
> > As part of any documentation change in rte_flow the developer would also need to update this table.
> > Why would it be very hard to maintain?
>  >
> 
> Ahh, that sound so simple when you say like this :) In practice even keeping 
> feature list requiring lots of effort, developers are 
> missing/neglecting/ignoring updating documentation when updating the code.
> 
> And for this case is partially correct table a useful information? If this is 
> not completely correct people won't rely on it and it will become just useless.
> So this feature should come with an automated way to detect if a rule supported 
> but not documented, or even better this table should be generated from code 
> automatically.
> 
> >>
> >>
> >> Let me start with a question, who do you think will be your consumer?
> >> Who will benefit from this table and how?
> > 
> > We get a lot of questions from users regarding rte_flow support and we do not have a single place with proper documentation.
> > I can ask the same about the overall feature table, right? There is a value to document the support.
> > 
> 
> Let's discuss the feature table separately, I think that is a valid question.
> 
> For the rte_flow, who is asking questions? End user, or application developer? 
> So is this intended to be a marketing documentation or technical documentation?
> 
> And what is the nature of the questions, if it is related to the rte_flow, there 
> is already a proper documentation for it:
> https://doc.dpdk.org/guides/prog_guide/rte_flow.html
> 
> If this question is if any specific rule supported by a specific PMD, right now 
> only valid way to say this that I am aware of is, run 'rte_flow_validate()' and see.
> Not sure if we can document this properly.

I think in general we are missing a big disclaimer
on top of this overview page:
	Each feature may have some hardware limitations.

Then there is a need, both for application developers and end-users,
to know which feature can be supported by a PMD,
or which PMD can support a feature.
Yes there are complex limitations with hardware offloads in general.
Yes it would be nice to report some tested capabilities with a CI.
But it does not mean we should not try to document it in my opinion.



  reply	other threads:[~2021-02-17 10:49 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-04 17:05 [dpdk-dev] [PATCH] " Asaf Penso
2021-02-04 22:09 ` Thomas Monjalon
2021-02-07  8:46   ` Asaf Penso
2021-02-07  9:44     ` Thomas Monjalon
2021-02-07  9:27 ` [dpdk-dev] [PATCH v2] " Asaf Penso
2021-02-07 10:46   ` [dpdk-dev] [PATCH v3] " Asaf Penso
2021-02-07 10:52     ` [dpdk-dev] [PATCH v4] " Asaf Penso
2021-02-08 12:58       ` Thomas Monjalon
2021-02-16 13:13       ` Ferruh Yigit
2021-02-17  5:57         ` Asaf Penso
2021-02-17 10:37           ` Ferruh Yigit
2021-02-17 10:49             ` Thomas Monjalon [this message]
2021-02-18 16:12               ` Asaf Penso
2021-02-18 17:58               ` Ajit Khaparde
2021-02-18 18:45                 ` Ferruh Yigit
2021-04-06 15:07                   ` Thomas Monjalon
2021-04-07 22:33 ` [dpdk-dev] [PATCH v5 0/3] rte_flow doc matrix Thomas Monjalon
2021-04-07 22:33   ` [dpdk-dev] [PATCH v5 1/3] doc: rename sfc features file Thomas Monjalon
2021-04-07 22:33   ` [dpdk-dev] [PATCH v5 2/3] doc: add flow API features tables Thomas Monjalon
2021-04-08  8:45     ` [dpdk-dev] [EXT] " Kiran Kumar Kokkilagadda
2021-05-14 10:42     ` [dpdk-dev] " Ferruh Yigit
2021-05-14 11:52       ` Thomas Monjalon
2021-04-07 22:33   ` [dpdk-dev] [PATCH v5 3/3] devtools: check flow API doc tables Thomas Monjalon
2021-05-13 18:40     ` Ferruh Yigit
2021-05-18 12:46       ` Thomas Monjalon
2021-05-14 10:51     ` Ferruh Yigit
2021-05-18 10:33       ` Thomas Monjalon
2021-05-18 13:28 ` [dpdk-dev] [PATCH v6 0/3] rte_flow doc matrix Thomas Monjalon
2021-05-18 13:28   ` [dpdk-dev] [PATCH v6 1/3] doc: rename sfc features file Thomas Monjalon
2021-05-18 13:28   ` [dpdk-dev] [PATCH v6 2/3] doc: add flow API features tables Thomas Monjalon
2021-05-18 13:28   ` [dpdk-dev] [PATCH v6 3/3] devtools: check flow API doc tables Thomas Monjalon
2021-05-18 16:54   ` [dpdk-dev] [PATCH v6 0/3] rte_flow doc matrix Thomas Monjalon

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=24451137.kzuPNkPQvE@thomas \
    --to=thomas@monjalon.net \
    --cc=ajit.khaparde@broadcom.com \
    --cc=arybchenko@solarflare.com \
    --cc=asafp@nvidia.com \
    --cc=dev@dpdk.org \
    --cc=ferruh.yigit@intel.com \
    --cc=galco@nvidia.com \
    --cc=jerinj@marvell.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

DPDK patches and discussions

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://inbox.dpdk.org/dev/0 dev/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 dev dev/ https://inbox.dpdk.org/dev \
		dev@dpdk.org
	public-inbox-index dev

Example config snippet for mirrors.
Newsgroup available over NNTP:
	nntp://inbox.dpdk.org/inbox.dpdk.dev


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git