DPDK-dev Archive on lore.kernel.org
 help / color / Atom feed
From: Andrew Rybchenko <arybchenko@solarflare.com>
To: Adrien Mazarguil <adrien.mazarguil@6wind.com>,
	Ori Kam <orika@mellanox.com>
Cc: Dekel Peled <dekelp@mellanox.com>,
	"wenzhuo.lu@intel.com" <wenzhuo.lu@intel.com>,
	"jingjing.wu@intel.com" <jingjing.wu@intel.com>,
	"bernard.iremonger@intel.com" <bernard.iremonger@intel.com>,
	Yongseok Koh <yskoh@mellanox.com>,
	Shahaf Shuler <shahafs@mellanox.com>,
	"dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v2 1/3] ethdev: add actions to modify TCP header fields
Date: Fri, 5 Apr 2019 14:54:49 +0300
Message-ID: <55805412-3145-4542-9376-67d02a62fa8b@solarflare.com> (raw)
In-Reply-To: <20190404132556.GS4889@6wind.com>

On 4/4/19 4:25 PM, Adrien Mazarguil wrote:
> Hi Ori,
>
> (trimming message down a bit)
>
> On Thu, Apr 04, 2019 at 09:01:52AM +0000, Ori Kam wrote:
>> Hi Adrien,
>>
>> PSB
> <snip>
>>> From: Adrien Mazarguil <adrien.mazarguil@6wind.com>
> <snip>
>>> On Wed, Apr 03, 2019 at 10:49:09AM +0000, Dekel Peled wrote:
>>>> Thanks, PSB.
> <snip>
>>>>> From: Adrien Mazarguil <adrien.mazarguil@6wind.com>
> <snip>
>>>>> I still don't agree with the wording as it implies one must combine this
>>> action
>>>>> with the TCP pattern item or else, while one should simply ensure the
>>>>> presence of TCP traffic somehow. This may be done by a prior filtering rule.
>>>>>
>>>>> So here's a generic suggestion which could be used with pretty much all
>>>>> modifying actions (other actions have the same problem and will have to be
>>>>> fixed as well eventually):
>>>>>
>>>>>   Using this action on non-matching traffic results in undefined behavior.
>>>>>
>>>>> This comment applies to all instances in this patch.
>>>> I accept your suggestion, indeed the existing actions have the problematic
>>> condition.
>>>> However I would like to currently leave this patch as-is for consistency.
>>>> I will send a fix patch for next release, applying the updated text to all
>>> modify-header actions.
>>>
>>> Please do it now as it's much more difficult to change an existing API
>>> later (think deprecation notices and endless discussions); even seemingly
>>> minor documentation issues like this one may affect applications.
>>>
>> I agree that changing API is not easy. This is why I think we should keep Dekel patch,
>> there is a number of API and consistency is very important. Also the PMD is based on the current
>> description that such command should fail.
>>
>> So lets keep it this way if you want to change all API then and only then this API should be changed.
> Wait, I'm not asking Delek to modify existing code/APIs right now, only to
> document these new actions properly from the start so we don't have to do it
> later (you even acknowledged it's more difficult that way).
>
> So I fail to understand why it's so important for their documentation to be
> consistent with unrelated and badly documented actions?
>
> Note the change I'm asking for at the API level doesn't affect PMD code,
> which remains free to put extra limitations (namely the presence of TCP
> pattern items). It's just that these limitations have nothing to do in the
> API itself.
>
> <snip>
>>>> It's either 2 actions with 1 parameters, or 1 action with 2 parameters.
>>>> The current implementation is more straight-forward in my opinion.
>>> I generally also prefer the one action per thing to do approach, but seeing
>>> the kind of actions you're adding, I fear we'll soon end up with lots of
>>> similar rte_flow_action_* structures modifying a single 32-bit value in some
>>> way.
>>>
>>> So for the same reasons as above, I think it's the right time to define a
>>> shared structure to rule them all, or maybe even let users provide a
>>> rte_be32_t/uint32_t/whatever pointer directly as a conf pointer (not
>>> as straightforward to document though).
>>>
>>> An object to rule them all would look something like that:
>>>
>>>   union rte_flow_integer {
>>>       rte_be64_t be64;
>>>       rte_le64_t le64;
>>>       uint64_t u64;
>>>       int64_t i64;
>>>       rte_be32_t be32;
>>>       rte_le32_t le32;
>>>       uint32_t u32;
>>>       int32_t i32;
>>>       uint8_t u8;
>>>       int8_t i8;
>>>   };
>>>
>>> Then actions that need a single integer value only have to document which
>>> field is relevant to them. How about that?

I like the idea (plus 16-bit options). We already have too many
rte_flow_action_* structures with single integer in it.

>> Like my previous comment. I understand your idea, but it has no huge advantage compared to the
>> suggested one by Dekel which also match all other API.
>>
>> Currently for each action we have a direct command, which is easy to understand by using your idea we break this concept.
> Yes, although not all actions have a configuration structure. Those that do
> indeed have a rte_flow_action_* counterpart, but it doesn't have to be
> unique, see RTE_FLOW_ITEM_GTP/GTPC/GTPU for instance.
>
> Likewise this patch adds struct rte_flow_action_modify_tcp_seq shared by
> RTE_FLOW_ACTION_TYPE_INC_TCP_SEQ and RTE_FLOW_ACTION_TYPE_DEC_TCP_SEQ
> although they lack a common prefix (inc_tcp/dec_tcp vs. modify_tcp). The
> type to use is covered by documentation and that's fine.
>
> So why not go a little further and share the exact same structure with
> RTE_FLOW_ACTION_TYPE_INC_TCP_ACK and RTE_FLOW_ACTION_TYPE_DEC_TCP_ACK?

Shouldn't these action be RTE_FLOW_ACTION_TYPE_MOD_TCP_{ACK,SEQ}
with singed 32-bit integer parameter (negative to decrement, positive to
increment)? IMHO, having INC and DEC is too artificial and just bloat API
and code.

> And while there, why not plan for subsequent actions that take a single
> integer value of some kind, because modifying existing APIs once upstream is
> complicated... See where I'm going?
>
>> There is no issue with having a large number of actions, it is even easer to read and document if each action is dedicated,
>> as you can also see from OVS.
> I'm actually fine with a large number of actions (rte_flow can support 2^31
> unique actions). Not so much with a large number of identical configuration
> structures that only differ by name associated with them. This is what I'd
> like to avoid before it's too late.

Too many actions bloat the code everywhere: API, PMDs, testpmd, other apps.
If it is possible to decrease number of different actions without
over-complicating, it should be done.

>> So I vote to keep Dekel patch as is.
> I don't, I guess another vote is needed to decide :)
>


  reply index

Thread overview: 76+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-21 14:18 [PATCH 0/3] add actions to modify " Dekel Peled
2019-03-21 14:18 ` [PATCH 1/3] ethdev: add actions to modify TCP " Dekel Peled
2019-03-26  9:24   ` Dekel Peled
2019-03-29 13:58   ` Adrien Mazarguil
2019-03-31 13:09     ` Dekel Peled
2019-03-21 14:18 ` [PATCH 2/3] app/testpmd: " Dekel Peled
2019-03-29 13:58   ` Adrien Mazarguil
2019-03-31 13:10     ` Dekel Peled
2019-03-21 14:18 ` [PATCH 3/3] net/mlx5: update modify header using Direct Verbs Dekel Peled
2019-04-02 15:13 ` [PATCH v2 0/3] add actions to modify header fields Dekel Peled
2019-04-10 11:26   ` [dpdk-dev] [PATCH v3 " Dekel Peled
2019-04-10 11:26     ` [dpdk-dev] [PATCH v3 1/3] ethdev: add actions to modify TCP " Dekel Peled
2019-04-10 11:26     ` [dpdk-dev] [PATCH v3 2/3] app/testpmd: " Dekel Peled
2019-04-10 11:26     ` [dpdk-dev] [PATCH v3 3/3] net/mlx5: update modify header using Direct Verbs Dekel Peled
2019-04-10 11:50     ` [dpdk-dev] [PATCH v4 0/3] add actions to modify header fields Dekel Peled
2019-04-10 11:50       ` [dpdk-dev] [PATCH v4 1/3] ethdev: add actions to modify TCP " Dekel Peled
2019-04-18 12:30         ` Adrien Mazarguil
2019-04-22  7:15           ` Dekel Peled
2019-04-10 11:50       ` [dpdk-dev] [PATCH v4 2/3] app/testpmd: " Dekel Peled
2019-04-10 11:50       ` [dpdk-dev] [PATCH v4 3/3] net/mlx5: update modify header using Direct Verbs Dekel Peled
2019-04-22 11:22       ` [dpdk-dev] [PATCH v5 0/3] add actions to modify header fields Dekel Peled
2019-04-22 11:22         ` [dpdk-dev] [PATCH v5 1/3] ethdev: add actions to modify TCP " Dekel Peled
2019-04-22 11:22         ` [dpdk-dev] [PATCH v5 2/3] app/testpmd: " Dekel Peled
2019-04-22 11:22         ` [dpdk-dev] [PATCH v5 3/3] net/mlx5: update modify header using Direct Verbs Dekel Peled
2019-06-02  8:18         ` [dpdk-dev] [PATCH v5 0/3] add actions to modify header fields Dekel Peled
2019-06-04  5:13           ` Dekel Peled
2019-06-04  8:14             ` Dekel Peled
2019-06-17  6:12         ` [dpdk-dev] [PATCH v6 " Dekel Peled
2019-06-17  6:12           ` [dpdk-dev] [PATCH v6 1/3] ethdev: add actions to modify TCP " Dekel Peled
2019-06-17  6:12           ` [dpdk-dev] [PATCH v6 2/3] app/testpmd: " Dekel Peled
2019-06-17  6:12           ` [dpdk-dev] [PATCH v6 3/3] net/mlx5: update modify header using Direct Verbs Dekel Peled
2019-06-27 17:39           ` [dpdk-dev] [PATCH v7 0/3] add actions to modify header fields Dekel Peled
2019-06-30  7:59             ` [dpdk-dev] [PATCH v8 " Dekel Peled
2019-06-30  7:59               ` [dpdk-dev] [PATCH v8 1/3] ethdev: add actions to modify TCP " Dekel Peled
2019-07-01  8:55                 ` Adrien Mazarguil
2019-07-01  9:58                   ` Dekel Peled
2019-06-30  7:59               ` [dpdk-dev] [PATCH v8 2/3] app/testpmd: " Dekel Peled
2019-06-30  7:59               ` [dpdk-dev] [PATCH v8 3/3] net/mlx5: update modify header using Direct Verbs Dekel Peled
     [not found]           ` <cover.1561656977.git.dekelp@mellanox.com>
2019-06-27 17:39             ` [dpdk-dev] [PATCH v7 1/3] ethdev: add actions to modify TCP header fields Dekel Peled
2019-06-27 17:54               ` Andrew Rybchenko
2019-06-28 16:18                 ` Adrien Mazarguil
2019-06-27 17:39             ` [dpdk-dev] [PATCH v7 2/3] app/testpmd: " Dekel Peled
2019-06-27 17:39             ` [dpdk-dev] [PATCH v7 3/3] net/mlx5: update modify header using Direct Verbs Dekel Peled
2019-04-02 15:13 ` [PATCH v2 1/3] ethdev: add actions to modify TCP header fields Dekel Peled
2019-04-02 16:33   ` Ori Kam
2019-04-03  9:14   ` Adrien Mazarguil
2019-04-03 10:49     ` Dekel Peled
2019-04-03 12:49       ` Adrien Mazarguil
2019-04-04  9:01         ` Ori Kam
2019-04-04 13:25           ` Adrien Mazarguil
2019-04-05 11:54             ` Andrew Rybchenko [this message]
2019-04-08 13:36             ` [dpdk-dev] " Dekel Peled
2019-04-08 13:53               ` Andrew Rybchenko
2019-04-08 14:21                 ` Adrien Mazarguil
2019-04-02 15:13 ` [PATCH v2 2/3] app/testpmd: " Dekel Peled
2019-04-02 16:33   ` Ori Kam
2019-04-02 15:13 ` [PATCH v2 3/3] net/mlx5: update modify header using Direct Verbs Dekel Peled
2019-04-02 16:34   ` Ori Kam
2019-04-03  8:27   ` Shahaf Shuler
2019-07-01 15:43 ` [dpdk-dev] [PATCH v9 0/3] add actions to modify header fields Dekel Peled
2019-07-01 15:43   ` [dpdk-dev] [PATCH v9 1/3] ethdev: add actions to modify TCP " Dekel Peled
2019-07-02  8:14     ` Andrew Rybchenko
2019-07-02  9:52       ` Dekel Peled
2019-07-02 10:33         ` Adrien Mazarguil
2019-07-02 12:01           ` Dekel Peled
2019-07-01 15:43   ` [dpdk-dev] [PATCH v9 2/3] app/testpmd: " Dekel Peled
2019-07-01 15:43   ` [dpdk-dev] [PATCH v9 3/3] net/mlx5: update modify header using Direct Verbs Dekel Peled
2019-07-02 14:44 ` [dpdk-dev] [PATCH v10 0/3] add actions to modify header fields Dekel Peled
2019-07-02 14:44   ` [dpdk-dev] [PATCH v10 1/3] ethdev: add actions to modify TCP " Dekel Peled
2019-07-03  5:04     ` Slava Ovsiienko
2019-07-02 14:44   ` [dpdk-dev] [PATCH v10 2/3] app/testpmd: " Dekel Peled
2019-07-03  6:30     ` Slava Ovsiienko
2019-07-02 14:44   ` [dpdk-dev] [PATCH v10 3/3] net/mlx5: update modify header using Direct Verbs Dekel Peled
2019-07-03  6:30     ` Slava Ovsiienko
2019-07-02 15:15   ` [dpdk-dev] [PATCH v10 0/3] add actions to modify header fields Adrien Mazarguil
2019-07-03 14:59     ` Ferruh Yigit

Reply instructions:

You may reply publically 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=55805412-3145-4542-9376-67d02a62fa8b@solarflare.com \
    --to=arybchenko@solarflare.com \
    --cc=adrien.mazarguil@6wind.com \
    --cc=bernard.iremonger@intel.com \
    --cc=dekelp@mellanox.com \
    --cc=dev@dpdk.org \
    --cc=jingjing.wu@intel.com \
    --cc=orika@mellanox.com \
    --cc=shahafs@mellanox.com \
    --cc=wenzhuo.lu@intel.com \
    --cc=yskoh@mellanox.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-dev Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/dpdk-dev/0 dpdk-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 dpdk-dev dpdk-dev/ https://lore.kernel.org/dpdk-dev \
		dev@dpdk.org dpdk-dev@archiver.kernel.org
	public-inbox-index dpdk-dev

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.dpdk.dev


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