On Fri, Apr 10, 2020 at 10:39:44AM +0530, Nithin Dabilpuram wrote:
> On Fri, Apr 10, 2020 at 01:07:17AM +0200, Andrzej Ostruszka wrote:
> > On 4/5/20 10:56 AM, jer...@marvell.com wrote:
> > > From: Nithin Dabilpuram <ndabilpu...@marvell.com>
> > >
> > > Add ctrl api to setup ethdev_rx and ethdev_tx node.
> > > This ctrl api clones 'N' number of ethdev_rx and ethdev_tx
> > > nodes with specific (port, queue) pairs updated in their context.
> > > All the ethdev ports and queues are setup before this api
> > > is called.
> > >
> > > Signed-off-by: Nithin Dabilpuram <ndabilpu...@marvell.com>
> > > Signed-off-by: Pavan Nikhilesh <pbhagavat...@marvell.com>
> > > Signed-off-by: Kiran Kumar K <kirankum...@marvell.com>
> > > ---
> > [...]
> > > +struct rte_node_mbuf_priv1 {
> > > + union {
> > > + /* IP4 rewrite */
> > > + struct {
> > > + uint16_t nh;
> > > + uint16_t ttl;
> > > + uint32_t cksum;
> > > + };
> > > +
> > > + uint64_t u;
> > > + };
> > > +};
> > > +
> > > +/**
> > > + * @warning
> > > + * @b EXPERIMENTAL: this API may change without prior notice
> > > + *
> > > + * Node mbuf private data to store crypto operation.
> > > + */
> > > +struct rte_node_mbuf_priv2 {
> > > + union {
> > > + /* Sym crypto */
> > > + struct {
> > > + struct rte_crypto_op op;
> > > + };
> > > + };
> > > +} __rte_cache_aligned;
> >
> > Why such definition?
>
> For communication b/w nodes, we need some per mbuf private space.
> We defined it into two halfs for performance reasons as
> #1 rte_node_mbuf_priv1(8 bytes) mapped to mbuf->udata64
> #2 rte_node_mbuf_priv2(RTE_CACHE_LINE_SIZE bytes) mapped to mbuf private area.
>
> #1 is smaller area and will not have a cache miss when accessed as mbuf
> is already in cache.
> #2 is larger area and probably good enough for many use cases like ipsec,
> crypto
> etc, and there will be an extra cost of cache miss to access it.
>
> Atleast in OCTEONTX2, we are able to see 27% performance drop, if use single
> private area #2 for everything instead.
>
> Since pkt_mbuf pool are created by application, we these structures are
> defined
> here have a check in ctrl api if the pkt_mbuf pool meets the mbuf private area
> size requirement.
Just wanted to update that I'll also rename this structure and
related api's to not start with "rte_" in next version
as they are not visible outside this librte_node library.
>
> >
> > With regards
> > Andrzej Ostruszka
