> -----Original Message-----
> From: Jerin Jacob <jerinjac...@gmail.com>
> Sent: Monday, February 6, 2023 10:08 PM
> To: Naga Harish K, S V <s.v.naga.haris...@intel.com>
> Cc: jer...@marvell.com; Carrillo, Erik G <erik.g.carri...@intel.com>; Gujjar,
> Abhinandan S <abhinandan.guj...@intel.com>; dev@dpdk.org;
> Jayatheerthan, Jay <jay.jayatheert...@intel.com>
> Subject: Re: [PATCH v2 1/3] eventdev/eth_rx: add params set/get APIs
>
> On Mon, Feb 6, 2023 at 11:52 AM Naga Harish K, S V
> <s.v.naga.haris...@intel.com> wrote:
> >
> > Hi Jerin,
> >
> > > -----Original Message-----
> > > From: Jerin Jacob <jerinjac...@gmail.com>
> > > Sent: Friday, February 3, 2023 3:15 PM
> > > To: Naga Harish K, S V <s.v.naga.haris...@intel.com>
> > > Cc: jer...@marvell.com; Carrillo, Erik G
> > > <erik.g.carri...@intel.com>; Gujjar, Abhinandan S
> > > <abhinandan.guj...@intel.com>; dev@dpdk.org; Jayatheerthan, Jay
> > > <jay.jayatheert...@intel.com>
> > > Subject: Re: [PATCH v2 1/3] eventdev/eth_rx: add params set/get APIs
> > >
> > > On Thu, Feb 2, 2023 at 9:42 PM Naga Harish K, S V
> > > <s.v.naga.haris...@intel.com> wrote:
> > > >
> > > > Hi Jerin,
> > > >
> > > > > -----Original Message-----
> > > > > From: Jerin Jacob <jerinjac...@gmail.com>
> > > > > Sent: Monday, January 30, 2023 8:13 PM
> > > > > To: Naga Harish K, S V <s.v.naga.haris...@intel.com>
> > > > > Cc: jer...@marvell.com; Carrillo, Erik G
> > > > > <erik.g.carri...@intel.com>; Gujjar, Abhinandan S
> > > > > <abhinandan.guj...@intel.com>; dev@dpdk.org; Jayatheerthan, Jay
> > > > > <jay.jayatheert...@intel.com>
> > > > > Subject: Re: [PATCH v2 1/3] eventdev/eth_rx: add params set/get
> > > > > APIs
> > > > >
> > > > > On Mon, Jan 30, 2023 at 3:26 PM Naga Harish K, S V
> > > > > <s.v.naga.haris...@intel.com> wrote:
> > > > > >
> > > > > >
> > > > > >
> > > > > > > -----Original Message-----
> > > > > > > From: Jerin Jacob <jerinjac...@gmail.com>
> > > > > > > Sent: Saturday, January 28, 2023 4:24 PM
> > > > > > > To: Naga Harish K, S V <s.v.naga.haris...@intel.com>
> > > > > > > Cc: jer...@marvell.com; Carrillo, Erik G
> > > > > > > <erik.g.carri...@intel.com>; Gujjar, Abhinandan S
> > > > > > > <abhinandan.guj...@intel.com>; dev@dpdk.org; Jayatheerthan,
> > > > > > > Jay <jay.jayatheert...@intel.com>
> > > > > > > Subject: Re: [PATCH v2 1/3] eventdev/eth_rx: add params
> > > > > > > set/get APIs
> > > > > > >
> > > > > > > On Wed, Jan 25, 2023 at 10:02 PM Naga Harish K, S V
> > > > > > > <s.v.naga.haris...@intel.com> wrote:
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > > -----Original Message-----
> > > > > > > > > From: Jerin Jacob <jerinjac...@gmail.com>
> > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > > > + */
> > > > > > > > > > > > > > + uint32_t rsvd[15];
> > > > > > > > > > > > > > + /**< Reserved fields for future use */
> > > > > > > > > > > > >
> > > > > > > > > > > > > Introduce
> > > > > > > > > > > > > rte_event_eth_rx_adapter_runtime_params_init()
> > > > > > > > > > > > > to
> > > > > > > > > make
> > > > > > > > > > > > > sure rsvd is zero.
> > > > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > The reserved fields are not used by the adapter or
> > > application.
> > > > > > > > > > > > Not sure Is it necessary to Introduce a new API to
> > > > > > > > > > > > clear reserved
> > > > > > > fields.
> > > > > > > > > > >
> > > > > > > > > > > When adapter starts using new fileds(when we add new
> > > > > > > > > > > fieds in future), the old applicaiton which is not
> > > > > > > > > > > using
> > > > > > > > > > > rte_event_eth_rx_adapter_runtime_params_init() may
> > > > > > > > > > > have
> > > > > junk
> > > > > > > > > > > value and then adapter implementation will behave bad.
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > does it mean, the application doesn't re-compile for
> > > > > > > > > > the new
> > > DPDK?
> > > > > > > > >
> > > > > > > > > Yes. No need recompile if ABI not breaking.
> > > > > > > > >
> > > > > > > > > > When some of the reserved fields are used in the
> > > > > > > > > > future, the application
> > > > > > > > > also may need to be recompiled along with DPDK right?
> > > > > > > > > > As the application also may need to use the newly
> > > > > > > > > > consumed reserved
> > > > > > > > > fields?
> > > > > > > > >
> > > > > > > > > The problematic case is:
> > > > > > > > >
> > > > > > > > > Adapter implementation of 23.07(Assuming there is change
> > > > > > > > > params) field needs to work with application of 23.03.
> > > > > > > > > rte_event_eth_rx_adapter_runtime_params_init() will sove
> that.
> > > > > > > > >
> > > > > > > >
> > > > > > > > As rte_event_eth_rx_adapter_runtime_params_init()
> > > > > > > > initializes only
> > > > > > > reserved fields to zero, it may not solve the issue in this case.
> > > > > > >
> > > > > > > rte_event_eth_rx_adapter_runtime_params_init() needs to zero
> > > > > > > all fields, not just reserved field.
> > > > > > > The application calling sequence is
> > > > > > >
> > > > > > > struct my_config c;
> > > > > > > rte_event_eth_rx_adapter_runtime_params_init(&c)
> > > > > > > c.interseted_filed_to_be_updated = val;
> > > > > > >
> > > > > > Can it be done like
> > > > > > struct my_config c = {0};
> > > > > > c.interseted_filed_to_be_updated = val; and update
> > > > > > Doxygen comments to recommend above usage to reset all fields?
> > > > > > This way, rte_event_eth_rx_adapter_runtime_params_init() can
> > > > > > be
> > > > > avoided.
> > > > >
> > > > > Better to have a function for documentation clarity. Similar
> > > > > scheme already there in DPDK. See rte_eth_cman_config_init()
> > > > >
> > > > >
> > > >
> > > >
> > > > The reference function rte_eth_cman_config_init() is resetting the
> > > > params
> > > struct and initializing the required params with default values in the pmd
> cb.
> > >
> > > No need for PMD cb.
> > >
> > > > The proposed rte_event_eth_rx_adapter_runtime_params_init () API
> > > > just
> > > needs to reset the params struct. There are no pmd CBs involved.
> > > > Having an API just to reset the struct seems overkill. What do you
> think?
> > >
> > > It is slow path API. Keeping it as function is better. Also, it
> > > helps the documentations of config parm in
> > > rte_event_eth_rx_adapter_runtime_params_config()
> > > like, This structure must be initialized with
> > > rte_event_eth_rx_adapter_runtime_params_init() or so.
> > >
> > >
> >
> > Are there any other reasons to have this API (*params_init()) other than
> documentation?
>
> Initialization code is segregated for tracking.
>
The discussed changes are updated in the v3 patchset.
> >
> > >
> > > >
> > > > > >
> > > > > > > Let me share an example and you can tell where is the issue
> > > > > > >
> > > > > > > 1)Assume parameter structure is 64B and for 22.03 8B are used.
> > > > > > > 2)rte_event_eth_rx_adapter_runtime_params_init() will clear all
> 64B.
> > > > > > > 3)There is an application written based on 22.03 which using
> > > > > > > only 8B after calling
> > > > > > > rte_event_eth_rx_adapter_runtime_params_init()
> > > > > > > 4)Assume, in 22.07 another 8B added to structure.
> > > > > > > 5)Now, the application (3) needs to run on 22.07. Since the
> > > > > > > application is calling
> > > > > > > rte_event_eth_rx_adapter_runtime_params_init()
> > > > > > > and 9 to 15B are zero, the implementation will not go bad.
> > > > > > >
> > > > > > > > The old application only tries to set/get previous valid
> > > > > > > > fields and the newly
> > > > > > > used fields may still contain junk value.
> > > > > > > > If the application wants to make use of any the newly used
> > > > > > > > params, the
> > > > > > > application changes are required anyway.
> > > > > > >
> > > > > > > Yes. If application wants to make use of newly added features.
> > > > > > > No need to change if new features are not needed for old
> application.
