From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: "Chautru, Nicolas" <nicolas.chautru@intel.com>,
Akhil Goyal <gakhil@marvell.com>,
Ferruh Yigit <ferruh.yigit@amd.com>,
"dev@dpdk.org" <dev@dpdk.org>,
"ferruh.yigit@xilinx.com" <ferruh.yigit@xilinx.com>,
Ray Kinsella <mdr@ashroe.eu>,
"thomas@monjalon.net" <thomas@monjalon.net>
Cc: "trix@redhat.com" <trix@redhat.com>,
"Richardson, Bruce" <bruce.richardson@intel.com>,
"david.marchand@redhat.com" <david.marchand@redhat.com>,
"stephen@networkplumber.org" <stephen@networkplumber.org>,
"Zhang, Mingshan" <mingshan.zhang@intel.com>,
"hemant.agrawal@nxp.com" <hemant.agrawal@nxp.com>
Subject: Re: [EXT] [PATCH v7 6/7] bbdev: add queue related warning and status information
Date: Fri, 30 Sep 2022 09:54:29 +0200 [thread overview]
Message-ID: <6b03d267-b292-7ed3-20cf-be330ac89595@redhat.com> (raw)
In-Reply-To: <BY5PR11MB445152BFC7CF245A89243521F8579@BY5PR11MB4451.namprd11.prod.outlook.com>
Hi Nic,
On 9/29/22 21:48, Chautru, Nicolas wrote:
> Hi Thomas,
> In absence of Ray (I did not see email from him for a some time) can you please advise on best option so that as to move on.
> I can either keep as is based on initial review with Ray, or replace _PADDED_MAX to _SIZE_MAX macro as suggested by Ferruh.
> I am happy either way as long as we are able to move forward. There is no full consensus but not strong opinion either from anyone.
I would go with Ferruh's suggestion.
Regards,
Maxime
> Thanks,
> Nic
>
>> -----Original Message-----
>> From: Akhil Goyal <gakhil@marvell.com>
>> Sent: Thursday, September 29, 2022 11:33 AM
>> To: Ferruh Yigit <ferruh.yigit@amd.com>; Chautru, Nicolas
>> <nicolas.chautru@intel.com>; dev@dpdk.org; Maxime Coquelin
>> <maxime.coquelin@redhat.com>; ferruh.yigit@xilinx.com; Ray Kinsella
>> <mdr@ashroe.eu>
>> Cc: thomas@monjalon.net; trix@redhat.com; Richardson, Bruce
>> <bruce.richardson@intel.com>; david.marchand@redhat.com;
>> stephen@networkplumber.org; Zhang, Mingshan
>> <mingshan.zhang@intel.com>; hemant.agrawal@nxp.com
>> Subject: RE: [EXT] [PATCH v7 6/7] bbdev: add queue related warning and status
>> information
>>
>>>> Thanks for your comment.
>>>> To be totally honest I don't yet see how your suggestion would be
>>>> better, but I
>>> quite possibly miss something. I did not reply in line with your
>>> comments so that to try to be clearer and avoid spreading the argument
>>> to much. Ray and Bruce feel free to chime in as well.
>>>>
>>>> First to state the obvious: Nothing will change the fact that in
>>>> case new enums
>>> are being added in DPDK, and if the application doesn't change, then
>>> user would not be able to interpret any such additional
>>> status/capability (backward compatible only feature parity and still
>>> ABI compliant) which is totally accepted as fine and up to the user,
>>> but the intention is at least not to have adverse effect even when
>>> they don’t update their code for such new features (notably in case
>>> they just use an older PMD not supporting such new features as a basic
>> typical example in the ecosystem). I think we agree on that problematic.
>>>>
>>>> In term of history of not using MAX value for enum, I believe there
>>>> is already
>>> well documented and you agree with the reasoning of why we had to move
>>> away from this [1]. Not just cosmetically where the max value is
>>> called an enum or a #define but to have application making hardcoded
>>> assumption on the possible maximum range for such enum notably when
>>> sizing array. The only caveat being that at the time, the community
>>> did spot the weakness but did not come to an agreement with regards to
>>> the best way to manage this moving forward.
>>>>
>>>> In case your point is purely cosmetic to rename the PADDED_MAX value
>>>> from
>>> the enum to a #define (both public) I don't see how this would make
>>> thing clearer by obfuscating the fact it is genuinely a padded value
>>> and to have that value directly related to the enum structure. Also
>>> note that there is already an actual max value defined for these enums
>>> (but kept private on purpose) which is used by the lib/bbdev functions
>>> to restrict usage to what is actually supported in the given implementation
>> (distinct from padded max value).
>>>>
>>>> Arguably the only concern I could understand in your message would
>>>> be this
>>> one " my concern was if user assumes all values valid until PADDED_MAX
>>> and tries to iterate array until that value".
>>>> But really the fact that it is indeed a padded value implies fairly
>>>> explicitly that
>>> we have padded the supported enums with placeholders enums not yet
>> defined.
>>> That is fairly tautological! I cannot see how it could confuse anyone.
>>> That is indeed to avoid such confusion that we went on that direction
>>> to expose a public future-proof padded maximum value.
>>>>
>>>> Then looking at usage in practice: when integrating the bbdev api
>>>> with higher
>>> level SW stacks (such as FlexRAN reference sw or 3rd party stacks) I
>>> don’t see how any of this theoretical concerns you raised would be
>>> relevant for any of these very cases (enqueue status, new capability
>>> etc...). The only genuine concern was sizing array based on MAX value being
>> not ABI compliant.
>>>> I cannot think of any code in the application presently deployed or
>>>> future that
>>> would then do what you are concerned about and cause an issue, and we
>>> definitely don’t do such things in any example for bbdev-test or in
>>> FlexRAN reference code provided to the ecosystem. The application
>>> would already have a default case when an enum being provided has no
>>> matching application, or more accurately in practice they would purely
>>> not look for these and hence these would be ignored seamlessly.
>>>>
>>>> Thanks again for the discussion. I wish this had happened earlier
>>>> (we only
>>> discussed this with Ray and Bruce while you were still at Intel), let
>>> me know what you think.
>>>> It may be more generally good moving forward to come to a general
>>> agreement at your technical forum level to avoid confusion. When we
>>> discussed earlier we came to the conclusion that the DPDK community
>>> had well documented what not to do to avoid ABI breakage but not
>>> necessarily what are the best alternatives.
>>>> Hopefully such future discussion should not delay this serie to be
>>>> applied but
>>> still let me know.
>>>>
>>>
>>> Hi Nic,
>>>
>>> I believe it is more clear/safe to convert to SIZE_MAX macros,
>>> although it is not a blocker.
>>>
>>> Anyway, I am not sure about the value of continuing this discussion,
>>> perhaps it is better to clarify the guidance for similar case with ABI
>>> maintainer and techboard, so it can proceed according to the decision.
>>>
>> I agree with Ferruh's comment for converting to SIZE_MAX macros.
>> However, it is not a strong comment from my side.
>> Moving to techboard would mean this patchset would skip the RC1 window.
>> I believe as Ray is the maintainer and go to person for ABI related issues.
>> I believe if he can take a look at the suggestion and provide ack/nack to
>> whichever Approach would be fine and we can go ahead in that direction.
>> I would like to close this as soon as possible. There are a lot of patches to be
>> blocked on this series.
>>
>> Regards,
>> Akhil
>
next prev parent reply other threads:[~2022-09-30 7:54 UTC|newest]
Thread overview: 174+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-09 0:22 [PATCH v1 0/2] bbdev: add device info on queue topology Nicolas Chautru
2022-03-09 0:22 ` [PATCH v1 1/2] " Nicolas Chautru
2022-03-09 1:28 ` Stephen Hemminger
2022-03-09 0:22 ` [PATCH v1 2/2] drivers/baseband: update PMDs to expose queue per operation Nicolas Chautru
2022-06-17 18:37 ` [PATCH v2 0/5] bbdev changes for 22.11 Nicolas Chautru
2022-06-17 18:37 ` [PATCH v2 1/5] bbdev: allow operation type enum for growth Nicolas Chautru
2022-06-17 18:37 ` [PATCH v2 2/5] bbdev: add device status info Nicolas Chautru
2022-06-17 18:37 ` [PATCH v2 3/5] bbdev: add device info on queue topology Nicolas Chautru
2022-06-17 18:37 ` [PATCH v2 4/5] drivers/baseband: update PMDs to expose queue per operation Nicolas Chautru
2022-06-17 18:37 ` [PATCH v2 5/5] bbdev: add new operation for FFT processing Nicolas Chautru
2022-06-28 1:35 ` [PATCH v3 0/7] bbdev changes for 22.11 Nicolas Chautru
2022-06-28 1:35 ` [PATCH v3 1/7] bbdev: allow operation type enum for growth Nicolas Chautru
2022-06-28 1:35 ` [PATCH v3 2/7] bbdev: add device status info Nicolas Chautru
2022-06-28 1:35 ` [PATCH v3 3/7] bbdev: add device info on queue topology Nicolas Chautru
2022-06-28 1:35 ` [PATCH v3 4/7] drivers/baseband: update PMDs to expose queue per operation Nicolas Chautru
2022-06-28 1:35 ` [PATCH v3 5/7] bbdev: add new operation for FFT processing Nicolas Chautru
2022-06-28 1:35 ` [PATCH v3 6/7] bbdev: add queue related warning and status information Nicolas Chautru
2022-06-28 1:35 ` [PATCH v3 7/7] bbdev: add a lock option for enqueue/dequeue operation Nicolas Chautru
2022-07-06 0:23 ` [PATCH v4 0/7] bbdev changes for 22.11 Nicolas Chautru
2022-07-06 0:23 ` [PATCH v4 1/7] bbdev: allow operation type enum for growth Nicolas Chautru
2022-07-06 12:50 ` Tom Rix
2022-07-06 21:20 ` Chautru, Nicolas
2022-07-06 0:23 ` [PATCH v4 2/7] bbdev: add device status info Nicolas Chautru
2022-07-06 15:38 ` Tom Rix
2022-07-06 21:16 ` Chautru, Nicolas
2022-07-07 13:37 ` Tom Rix
2022-07-07 17:15 ` Chautru, Nicolas
2022-07-18 13:09 ` Tom Rix
2022-08-25 14:08 ` Maxime Coquelin
2022-07-06 0:23 ` [PATCH v4 3/7] bbdev: add device info on queue topology Nicolas Chautru
2022-07-06 16:06 ` Tom Rix
2022-07-06 21:12 ` Chautru, Nicolas
2022-07-07 13:34 ` Tom Rix
2022-07-07 17:13 ` Chautru, Nicolas
2022-07-18 13:04 ` Tom Rix
2022-07-06 0:23 ` [PATCH v4 4/7] drivers/baseband: update PMDs to expose queue per operation Nicolas Chautru
2022-07-06 16:15 ` Tom Rix
2022-07-06 21:10 ` Chautru, Nicolas
2022-07-07 13:20 ` Tom Rix
2022-07-07 17:19 ` Chautru, Nicolas
2022-07-18 13:21 ` Tom Rix
2022-08-15 17:28 ` Chautru, Nicolas
2022-07-06 0:23 ` [PATCH v4 5/7] bbdev: add new operation for FFT processing Nicolas Chautru
2022-07-06 18:47 ` Tom Rix
2022-07-06 21:04 ` Chautru, Nicolas
2022-07-07 13:09 ` Tom Rix
2022-07-07 16:57 ` Chautru, Nicolas
2022-07-18 22:38 ` Tom Rix
2022-07-06 0:23 ` [PATCH v4 6/7] bbdev: add queue related warning and status information Nicolas Chautru
2022-07-06 18:57 ` Tom Rix
2022-07-06 20:34 ` Chautru, Nicolas
2022-07-06 0:23 ` [PATCH v4 7/7] bbdev: add a lock option for enqueue/dequeue operation Nicolas Chautru
2022-07-06 19:01 ` Tom Rix
2022-07-06 19:20 ` Stephen Hemminger
2022-07-06 20:21 ` Chautru, Nicolas
2022-07-07 12:47 ` Tom Rix
2022-07-06 23:28 ` [PATCH v5 0/7] bbdev changes for 22.11 Nicolas Chautru
2022-07-06 23:28 ` [PATCH v5 1/7] bbdev: allow operation type enum for growth Nicolas Chautru
2022-08-25 13:54 ` Maxime Coquelin
2022-07-06 23:28 ` [PATCH v5 2/7] bbdev: add device status info Nicolas Chautru
2022-08-25 14:18 ` Maxime Coquelin
2022-08-25 18:30 ` Chautru, Nicolas
2022-08-26 10:12 ` Maxime Coquelin
2022-08-29 16:10 ` Chautru, Nicolas
2022-08-30 7:08 ` Maxime Coquelin
2022-08-30 19:38 ` Chautru, Nicolas
2022-07-06 23:28 ` [PATCH v5 3/7] bbdev: add device info on queue topology Nicolas Chautru
2022-08-25 15:23 ` Maxime Coquelin
2022-07-06 23:28 ` [PATCH v5 4/7] drivers/baseband: update PMDs to expose queue per operation Nicolas Chautru
2022-07-06 23:28 ` [PATCH v5 5/7] bbdev: add new operation for FFT processing Nicolas Chautru
2022-07-06 23:28 ` [PATCH v5 6/7] bbdev: add queue related warning and status information Nicolas Chautru
2022-07-06 23:28 ` [PATCH v5 7/7] bbdev: remove unnecessary if-check Nicolas Chautru
2022-08-15 17:54 ` [PATCH v5 0/7] bbdev changes for 22.11 Chautru, Nicolas
2022-08-25 18:24 ` [PATCH v6 " Nicolas Chautru
2022-08-25 18:24 ` [PATCH v6 1/7] bbdev: allow operation type enum for growth Nicolas Chautru
2022-08-25 18:24 ` [PATCH v6 2/7] bbdev: add device status info Nicolas Chautru
2022-08-25 18:24 ` [PATCH v6 3/7] bbdev: add device info on queue topology Nicolas Chautru
2022-08-25 18:24 ` [PATCH v6 4/7] drivers/baseband: update PMDs to expose queue per operation Nicolas Chautru
2022-08-26 11:53 ` Maxime Coquelin
2022-08-25 18:24 ` [PATCH v6 5/7] bbdev: add new operation for FFT processing Nicolas Chautru
2022-08-26 12:07 ` Maxime Coquelin
2022-08-29 18:18 ` Chautru, Nicolas
2022-08-25 18:24 ` [PATCH v6 6/7] bbdev: add queue related warning and status information Nicolas Chautru
2022-08-26 19:51 ` Maxime Coquelin
2022-08-25 18:24 ` [PATCH v6 7/7] bbdev: remove unnecessary if-check Nicolas Chautru
2022-08-26 19:52 ` Maxime Coquelin
2022-08-29 18:07 ` [PATCH v7 0/7] bbdev changes for 22.11 Nicolas Chautru
2022-08-29 18:07 ` [PATCH v7 1/7] bbdev: allow operation type enum for growth Nicolas Chautru
2022-08-29 18:07 ` [PATCH v7 2/7] bbdev: add device status info Nicolas Chautru
2022-08-30 2:19 ` Zhang, Mingshan
2022-08-30 4:43 ` Hemant Agrawal
2022-09-21 18:54 ` [EXT] " Akhil Goyal
2022-09-21 20:53 ` Chautru, Nicolas
2022-08-29 18:07 ` [PATCH v7 3/7] bbdev: add device info on queue topology Nicolas Chautru
2022-08-29 18:07 ` [PATCH v7 4/7] drivers/baseband: update PMDs to expose queue per operation Nicolas Chautru
2022-08-30 4:44 ` Hemant Agrawal
2022-09-21 19:00 ` [EXT] " Akhil Goyal
2022-09-21 20:53 ` Chautru, Nicolas
2022-08-29 18:07 ` [PATCH v7 5/7] bbdev: add new operation for FFT processing Nicolas Chautru
2022-09-21 19:14 ` [EXT] " Akhil Goyal
2022-09-21 20:56 ` Chautru, Nicolas
2022-09-22 14:19 ` Akhil Goyal
2022-09-22 16:39 ` Chautru, Nicolas
2022-09-22 16:48 ` Akhil Goyal
2022-09-22 17:25 ` Chautru, Nicolas
2022-08-29 18:07 ` [PATCH v7 6/7] bbdev: add queue related warning and status information Nicolas Chautru
2022-09-21 19:21 ` [EXT] " Akhil Goyal
2022-09-21 20:57 ` Chautru, Nicolas
2022-09-23 10:57 ` Ferruh Yigit
[not found] ` <CO6PR18MB44848717BA4EA2FF8967D7CBD8509@CO6PR18MB4484.namprd18.prod.outlook.com>
2022-09-24 16:34 ` Chautru, Nicolas
2022-09-27 9:43 ` Ferruh Yigit
2022-09-27 20:59 ` Chautru, Nicolas
2022-09-29 18:10 ` Ferruh Yigit
2022-09-29 18:32 ` Akhil Goyal
2022-09-29 19:48 ` Chautru, Nicolas
2022-09-30 7:54 ` Maxime Coquelin [this message]
2022-08-29 18:07 ` [PATCH v7 7/7] bbdev: remove unnecessary if-check Nicolas Chautru
2022-09-21 19:25 ` [EXT] " Akhil Goyal
2022-09-21 20:58 ` Chautru, Nicolas
2022-08-30 4:45 ` [PATCH v7 0/7] bbdev changes for 22.11 Hemant Agrawal
2022-09-06 16:47 ` Chautru, Nicolas
2022-09-21 21:02 ` [PATCH v8 " Nic Chautru
2022-09-21 21:02 ` [PATCH v8 1/7] bbdev: allow operation type enum for growth Nic Chautru
2022-09-21 21:02 ` [PATCH v8 2/7] bbdev: add device status info Nic Chautru
2022-09-21 21:02 ` [PATCH v8 3/7] bbdev: add device info on queue topology Nic Chautru
2022-09-21 21:02 ` [PATCH v8 4/7] drivers/baseband: update PMDs to expose queue per operation Nic Chautru
2022-09-21 21:02 ` [PATCH v8 5/7] bbdev: add new operation for FFT processing Nic Chautru
2022-09-21 21:02 ` [PATCH v8 6/7] bbdev: add queue related warning and status information Nic Chautru
2022-09-21 21:02 ` [PATCH v8 7/7] bbdev: remove unnecessary if-check Nic Chautru
2022-09-22 17:45 ` [PATCH v9 0/7] bbdev changes for 22.11 Nic Chautru
2022-09-22 17:45 ` [PATCH v9 1/7] bbdev: allow operation type enum for growth Nic Chautru
2022-09-22 17:45 ` [PATCH v9 2/7] bbdev: add device status info Nic Chautru
2022-09-22 17:45 ` [PATCH v9 3/7] bbdev: add device info on queue topology Nic Chautru
2022-09-22 17:45 ` [PATCH v9 4/7] drivers/baseband: update PMDs to expose queue per operation Nic Chautru
2022-09-22 17:45 ` [PATCH v9 5/7] bbdev: add new operation for FFT processing Nic Chautru
2022-09-22 17:45 ` [PATCH v9 6/7] bbdev: add queue related warning and status information Nic Chautru
2022-09-22 17:45 ` [PATCH v9 7/7] bbdev: remove unnecessary if-check Nic Chautru
2022-09-22 18:17 ` [EXT] [PATCH v9 0/7] bbdev changes for 22.11 Akhil Goyal
2022-09-22 20:59 ` Chautru, Nicolas
2022-09-30 18:45 ` [PATCH v10 " Nicolas Chautru
2022-09-30 18:45 ` [PATCH v10 1/7] bbdev: allow operation type enum for growth Nicolas Chautru
2022-09-30 18:46 ` [PATCH v10 2/7] bbdev: add device status info Nicolas Chautru
2022-09-30 18:46 ` [PATCH v10 3/7] bbdev: add device info on queue topology Nicolas Chautru
2022-09-30 18:46 ` [PATCH v10 4/7] drivers/baseband: update PMDs to expose queue per operation Nicolas Chautru
2022-09-30 18:46 ` [PATCH v10 5/7] bbdev: add new operation for FFT processing Nicolas Chautru
2022-09-30 18:46 ` [PATCH v10 6/7] bbdev: add queue related warning and status information Nicolas Chautru
2022-10-03 8:28 ` Thomas Monjalon
2022-10-03 16:39 ` Chautru, Nicolas
2022-10-03 17:21 ` Thomas Monjalon
2022-09-30 18:46 ` [PATCH v10 7/7] bbdev: remove unnecessary if-check Nicolas Chautru
2022-09-30 20:38 ` [EXT] [PATCH v10 0/7] bbdev changes for 22.11 Akhil Goyal
2022-10-03 18:00 ` [PATCH v11 " Nicolas Chautru
2022-10-03 18:00 ` [PATCH v11 1/7] bbdev: allow operation type enum for growth Nicolas Chautru
2022-10-03 18:00 ` [PATCH v11 2/7] bbdev: add device status info Nicolas Chautru
2022-10-03 18:00 ` [PATCH v11 3/7] bbdev: add device info on queue topology Nicolas Chautru
2022-10-03 18:00 ` [PATCH v11 4/7] drivers/baseband: update PMDs to expose queue per operation Nicolas Chautru
2022-10-03 18:00 ` [PATCH v11 5/7] bbdev: add new operation for FFT processing Nicolas Chautru
2022-10-03 18:00 ` [PATCH v11 6/7] bbdev: add queue related warning and status information Nicolas Chautru
2022-10-03 18:00 ` [PATCH v11 7/7] bbdev: remove unnecessary if-check Nicolas Chautru
2022-10-04 17:16 ` [PATCH v12 0/7] bbdev changes for 22.11 Nicolas Chautru
2022-10-04 17:16 ` [PATCH v12 1/7] bbdev: allow operation type enum for growth Nicolas Chautru
2022-10-04 17:16 ` [PATCH v12 2/7] bbdev: add device status info Nicolas Chautru
2022-10-05 7:16 ` Maxime Coquelin
2022-10-04 17:16 ` [PATCH v12 3/7] bbdev: add device info on queue topology Nicolas Chautru
2022-10-04 17:16 ` [PATCH v12 4/7] drivers/baseband: update PMDs to expose queue per operation Nicolas Chautru
2022-10-04 17:16 ` [PATCH v12 5/7] bbdev: add new operation for FFT processing Nicolas Chautru
2022-10-04 17:16 ` [PATCH v12 6/7] bbdev: add queue related warning and status information Nicolas Chautru
2022-10-04 17:16 ` [PATCH v12 7/7] bbdev: remove unnecessary if-check Nicolas Chautru
2022-10-06 17:31 ` [EXT] [PATCH v12 0/7] bbdev changes for 22.11 Akhil Goyal
2022-10-06 22:28 ` Chautru, Nicolas
2022-10-07 4:46 ` Akhil Goyal
2022-10-10 7:35 ` Thomas Monjalon
2022-10-10 17:07 ` Chautru, Nicolas
2022-06-06 16:15 ` [PATCH v1 0/2] bbdev: add device info on queue topology Chautru, Nicolas
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