[dpdk-dev] [PATCH v2 04/13] ethdev: support of multiple sizes of redirection table

[Zhang, Helin]

Hi Thomas

> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com]
> Sent: Tuesday, October 28, 2014 6:10 PM
> To: Zhang, Helin
> Cc: dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v2 04/13] ethdev: support of multiple sizes of
> redirection table
> 
> 2014-10-28 00:33, Zhang, Helin:
> > From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com]
> > > 2014-09-25 16:40, Helin Zhang:
> > > >  /* Definitions used for redirection table entry size */ -#define
> > > > ETH_RSS_RETA_NUM_ENTRIES 128
> > > > -#define ETH_RSS_RETA_MAX_QUEUE   16
> > > > +#define ETH_RSS_RETA_SIZE_64  64
> > > > +#define ETH_RSS_RETA_SIZE_128 128 #define ETH_RSS_RETA_SIZE_512
> > > > +512
> > > > +
> > > > +#define RTE_BIT_WIDTH_64 (CHAR_BIT * sizeof(uint64_t))
> > >
> > > Are these constants really needed?
> >
> > These constants were defined for the third input parameter of
> > rte_eth_dev_rss_reta_update() and rte_eth_dev_rss_reta_query(). End
> > users need to give the correct reta size listed as above, as other
> > values is not valid. So it would be better to list the valid reta sizes in macros
> here.
> 
> OK, so you should explain that only these values are allowed.
> In general, it's something we explain in the comment of the function
It would be better to add comments for the functions.

> 
> By the way, why only these values are allowed?
It depends on hardware, 1G/10G hardware supports 128 reta size only, 40G
hardware supports 512 or 128 depends on hardware configuration, 40G VF
hardware supports 64. If more is introduced in the future, more values can be
added later. It will return with errors if reta size is not supported for specific hardware.

> 
> --
> Thomas

Regards,
Helin