Re: [dpdk-dev] [PATCH v1 2/4] regexdev: add regex core h file

[Ori Kam <orika@mellanox.com>]

Hi Guy,

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Guy Kaneti
> Sent: Tuesday, April 7, 2020 11:54 AM
> To: Ori Kam <orika@mellanox.com>; Jerin Jacob Kollanukkaran
> <jerinj@marvell.com>; xiang.w.wang@intel.com
> Cc: dev@dpdk.org; Pavan Nikhilesh Bhagavatula
> <pbhagavatula@marvell.com>; Shahaf Shuler <shahafs@mellanox.com>;
> hemant.agrawal@nxp.com; Opher Reviv <opher@mellanox.com>; Alex
> Rosenbaum <alexr@mellanox.com>; Dovrat Zifroni <dovrat@marvell.com>;
> Prasun Kapoor <pkapoor@marvell.com>; nipun.gupta@nxp.com;
> bruce.richardson@intel.com; yang.a.hong@intel.com; harry.chang@intel.com;
> gu.jian1@zte.com.cn; shanjiangh@chinatelecom.cn;
> zhangy.yun@chinatelecom.cn; lixingfu@huachentel.com; wushuai@inspur.com;
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> hongjun.ni@intel.com; j.bromhead@titan-ic.com; deri@ntop.org;
> fc@napatech.com; arthur.su@lionic.com; Thomas Monjalon
> <thomas@monjalon.net>; Parav Pandit <parav@mellanox.com>
> Subject: Re: [dpdk-dev] [PATCH v1 2/4] regexdev: add regex core h file
> 
> > +
> > +/**
> > + * @internal
> > + * The generic data structure associated with each RegEx device.
> > + *
> > + * Pointers to burst-oriented packet receive and transmit functions are
> > + * located at the beginning of the structure, along with the pointer to
> > + * where all the data elements for the particular device are stored in
> > +shared
> > + * memory. This split allows the function pointer and driver data to be
> > +per-
> > + * process, while the actual configuration data for the device is shared.
> > + */
> > +struct rte_regexdev {
> > +	regexdev_enqueue_t enqueue;
> > +	regexdev_dequeue_t dequeue;
> > +	const struct rte_regexdev_ops *dev_ops;
> > +	/**< Functions exported by PMD */
> > +	struct rte_device *device; /**< Backing device */ }
> > +__rte_cache_aligned;
> > +
> 
> What about a handle for the PMD private data such as
> 	struct rte_eventdev_data *data;
> 	/**< Pointer to device data */
> 
> 	struct rte_cryptodev_data *data;
> 	/**< Pointer to device data */

I was thinking about new approach. To use container of.
Meaning each PMD will create like normal its priv structure.
In this structure there will be a regex_dev member.
For example:
struct mlx5_regex_priv {
	struct rte_regex_dev regex_dev;
	//private fields
	...
	...
}
On registration the PMD will give the rte_regexdev the reference to the regex_dev.
The PMD will use container_of

This approach  hides the private data from the application,
saves malloc, a bit faster, and saves the use of references.

So a better approach 😊 also this approach is in use by the rte_device.