Re: [dpdk-dev] [PATCH v4 3/4] eventdev: Add eventdev ethernet Rx adapter

["Rao, Nikhil" <nikhil.rao@intel.com>]

On 10/3/2017 7:22 PM, Jerin Jacob wrote:
> -----Original Message-----
>> Date: Sun, 24 Sep 2017 23:46:51 +0530
>> From: "Rao, Nikhil" <nikhil.rao@intel.com>
>> To: Jerin Jacob <jerin.jacob@caviumnetworks.com>
>> CC: bruce.richardson@intel.com, gage.eads@intel.com, dev@dpdk.org,
>>   thomas@monjalon.net, harry.van.haaren@intel.com, hemant.agrawal@nxp.com,
>>   nipun.gupta@nxp.com, narender.vangati@intel.com,
>>   erik.g.carrillo@intel.com, abhinandan.gujjar@intel.com,
>>   santosh.shukla@caviumnetworks.com
>> Subject: Re: [PATCH v4 3/4] eventdev: Add eventdev ethernet Rx adapter
>> User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101
>>   Thunderbird/52.3.0
>>
>>
>> OK, Thanks for the detailed review. Will add the programmer guide to RC1.
> 
> OK. Thanks.
> 
>>
>>>
>>>
>>>
>> Yes, if create() and queue_add() are called from different processes, it
>> wouldn't work.
>>
>>>> +
>>>> +static uint8_t default_rss_key[] = {
>>>> +	0x6d, 0x5a, 0x56, 0xda, 0x25, 0x5b, 0x0e, 0xc2,
>>>> +	0x41, 0x67, 0x25, 0x3d, 0x43, 0xa3, 0x8f, 0xb0,
>>>> +	0xd0, 0xca, 0x2b, 0xcb, 0xae, 0x7b, 0x30, 0xb4,
>>>> +	0x77, 0xcb, 0x2d, 0xa3, 0x80, 0x30, 0xf2, 0x0c,
>>>> +	0x6a, 0x42, 0xb7, 0x3b, 0xbe, 0xac, 0x01, 0xfa,
>>>> +};
>>>
>>> Looks like the scope of this array is only for rte_event_eth_rx_adapter_init,
>>> if so please move it to stack.
>>>
>> OK.
>>
>>>
>>>> +static uint8_t *rss_key_be;
>>>
>>> Can we remove this global variable add it in in adapter memory?
>>>
>>
>> There is currently struct rte_event_eth_rx_adapter
>> **rte_event_eth_rx_adapter that is an array of pointers to the adapters.
>> rss_key_be points to memory after this array.
>>
>> are you thinking of something like:
>>
>> struct {
>> struct rte_event_eth_rx_adapter **rte_event_eth_rx_adapter
>> uint8_t *rss_key_be;
>> } global;
> 
> I was thinking, to hold 40B in struct rte_event_eth_rx_adapter for
> rss_key_be and initialize per rx_adapter to avoid global variable
> as fill_event_buffer() has access to rte_event_eth_rx_adapter.
> 
> Something like below as rough idea.
> ➜ [dpdk-next-eventdev] $ git diff
> lib/librte_eventdev/rte_event_eth_rx_adapter.c
> diff --git a/lib/librte_eventdev/rte_event_eth_rx_adapter.c
> b/lib/librte_eventdev/rte_event_eth_rx_adapter.c
> index cd19e7c28..ba6148931 100644
> --- a/lib/librte_eventdev/rte_event_eth_rx_adapter.c
> +++ b/lib/librte_eventdev/rte_event_eth_rx_adapter.c
> @@ -37,6 +37,7 @@ struct rte_eth_event_enqueue_buffer {
>   };
>   
>   struct rte_event_eth_rx_adapter {
> +       uint8_t rss_key[40];
>          /* event device identifier */
>          uint8_t eventdev_id;
>          /* per ethernet device structure */

OK.


>>>> +
>>>> +static int
>>>> +default_conf_cb(uint8_t id, uint8_t dev_id,
>>>> +		struct rte_event_eth_rx_adapter_conf *conf, void *arg)
>>>> +{
>>>> +
>>>> +	ret = rte_event_port_setup(dev_id, port_id, port_conf);
>>>> +	if (ret) {
>>>> +		RTE_EDEV_LOG_ERR("failed to setup event port %u\n",
>>>> +					port_id);
>>>
>>> return or add goto to exit from here to avoid calling rte_event_dev_start below
>>>
>> Could do the return but I wanted to leave the device in the same state as it
>> was at entry into this function. Thoughts ?
> 
> Will calling rte_event_dev_start() down(in case if wont return) change
> the state? if not, it is fine.
> 

OK, will put in the return. if the device were configured with an 
additional port and the setup for this port fails. The 
rte_event_dev_start() call will dereference a NULL ptr.

Nikhil



> No another comments. Looks good to me.
> 
>