Re: [PATCH v4 5/9] lib/librte_pdump: add new library for packet capturing support

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: Pattan, Reshma
> Sent: Friday, May 27, 2016 3:55 PM
> To: Ananyev, Konstantin; dev@dpdk.org
> Cc: Pattan, Reshma
> Subject: RE: [dpdk-dev] [PATCH v4 5/9] lib/librte_pdump: add new library for packet capturing support
> 
> 
> 
> > -----Original Message-----
> > From: Ananyev, Konstantin
> > Sent: Friday, May 27, 2016 2:39 PM
> > To: Pattan, Reshma <reshma.pattan@intel.com>; dev@dpdk.org
> > Cc: Pattan, Reshma <reshma.pattan@intel.com>
> > Subject: RE: [dpdk-dev] [PATCH v4 5/9] lib/librte_pdump: add new library for
> > packet capturing support
> >
> > Hi Reshma,
> 
> > > +static int
> > > +pdump_regitser_callbacks(uint32_t dir, uint16_t end_q,
> > > +			uint8_t port, uint16_t queue,
> > > +			struct rte_ring *ring, struct rte_mempool *mp,
> > > +			uint16_t operation)
> > > +{
> > > +
> > > +	uint16_t qid;
> > > +	struct pdump_rxtx_cbs *cbs = NULL;
> > > +
> > > +	qid = (queue == RTE_PDUMP_ALL_QUEUES) ? 0 : queue;
> > > +	for (; qid < end_q; qid++) {
> > > +		if ((dir & RTE_PDUMP_FLAG_RX) != 0)
> > > +			cbs = &rx_cbs[port][qid];
> > > +		if ((dir & RTE_PDUMP_FLAG_TX) != 0)
> > > +			cbs = &tx_cbs[port][qid];
> >
> > In case you have dir == (RTE_PDUMP_FLAG_RX | RTE_PDUMP_FLAG_TX) you'll
> > overwrite your rx_cbs pointer with tx_cbs pointer.
> > I suppose you need 2 local vars: cbs_rx and cbs_tx here.
> > Again probably worth to have 2 helper functions:
> > pdump_regitser_rx_callback() and pdump_regitser_tx_callback() and call them
> > from that one.
> > Or you'll never invoke that function with dir ==(RTE_PDUMP_FLAG_RX |
> > RTE_PDUMP_FLAG_TX)?
> > If so, it porbably worth to put it into comments, though if it would be me, I still
> > think it would be good to split it in a way I mentioned above.
> >
> 
> Yes,  I never invoke the function with dir ==(RTE_PDUMP_FLAG_RX | RTE_PDUMP_FLAG_TX).

Ok, then at least probably comment it somehow.
Though I still think 2 different variables (and might be functions) would be better.

> 
> > > +
> > > +	dir = p->dir;
> > > +	operation = p->op;
> > > +	if (operation == ENABLE) {
> > > +		if (p->data.en_v1.is_pci_or_name == true) {
> > > +			/* check if device is pci address or name */
> > > +			if (pdump_get_dombdf(p->data.en_v1.device, domBDF)
> > == 0)
> > > +				ret = rte_eth_dev_get_port_by_name(domBDF,
> > &port);
> > > +			else
> > > +				ret = rte_eth_dev_get_port_by_name(p-
> > >data.en_v1.device,
> > > +
> > 	&port);
> >
> >
> > Why we can't force client to have device name in predefined format?
> > Then you woudn't need that name conversion here.
> 
> You mean  I should do the conversion pdump_get_dombdf() in client and then pass that value to server?

Yes.

> 
> >
> > > +			if (ret < 0) {
> > > +				RTE_LOG(ERR, PDUMP,
> > > +					"failed to get potid for device
> > id=%s\n",
> > > +					p->data.en_v1.device);
> > > +				return -EINVAL;
> > > +			}
> > > +		} else /* if device is port id */
> > > +			port = atoi(p->data.en_v1.device);
> >
> > Hmm, again why not make server to accept requests only by device id?
> > Then it would be client responsibility to do port to device id, and you can get rid
> > of some duplicated code here.
> 
> If client is secondary process then  the same port id on primary and secondary processes might be mapping to different devices right?

Yes.

> If so I cannot do port id to device name conversion in client.


Ok, but the client can do either port_enable/disable by client port id,
or (if that device is not mapped on the client) by device_id.

Konstantin


> 
> Thanks,
> Reshma