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

[Jerin Jacob]

On Wed, Apr 8, 2020 at 1:07 PM Ori Kam <orika at mellanox.com> wrote:

>
>
> > -----Original Message-----
> > From: dev <dev-bounces at dpdk.org> On Behalf Of Jerin Jacob
> > Sent: Tuesday, April 7, 2020 7:27 PM
> > Subject: Re: [dpdk-dev] [PATCH v1 2/4] regexdev: add regex core h file
> >
> > On Tue, Apr 7, 2020 at 9:46 PM Ori Kam <orika at mellanox.com> wrote:
> >
> > > Hi Guy,
> > >
> > > > -----Original Message-----
> > > > From: dev <dev-bounces at dpdk.org> On Behalf Of Guy Kaneti
> > > > Sent: Tuesday, April 7, 2020 11:54 AM
> > > > > +
> > > > > +/**
> > > > > + * @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;
> > >
> >
> > The  rte_regex_dev which has  enqueue() and  dequeue() function pointer
> > should not be NOT allocated from hugepage
> > as per process it will have different enqueue() and dequeue() function
> > pointer value. Making it hugepage, another process
> > overwrites it.
> >
> >
>
> I didn't say this structure should be allocated from huge page.
> Unless I'm missing something, from memory this is exactly the same
> as if we had pointer to the priv.
>

Private data should be allocated from the hugepage so that multiple
processes can access it.
Whereas the memory that contains the  enqueue() and dequeue() should not
be  from hugepage.
So both can not be from the same memory. Right?




> >
> > >         //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.
> > >
> > >
> > >
>