Matias Elo(matiaselo) replied on github web page:
platform/linux-generic/pktio/dpdk.c
line 70
@@ -1372,10 +1382,10 @@ static int dpdk_recv(pktio_entry_t *pktio_entry, int
index,
if (!pkt_dpdk->lockless_rx)
odp_ticketlock_lock(&pkt_dpdk->rx_lock[index]);
/**
- * ixgbe_pmd has a minimum supported RX burst size ('min_rx_burst'). If
- * 'num' < 'min_rx_burst', 'min_rx_burst' is used as rte_eth_rx_burst()
- * argument and the possibly received extra packets are cached for the
- * next dpdk_recv_queue() call to use.
+ * ixgbe and i40e drivers have a minimum supported RX burst size
Comment:
@Bill-Fischofer-Linaro Yes, the application has to request at least
'min_rx_burst' packets but it may receive less.
> Matias Elo(matiaselo) wrote:
> @nagarahalli This dpdk driver "feature" can be completely hidden from odp
> applications (and it already is), so I don't support adding a new device
> capability parameter. This would make writing simple applications more
> complex. E.g. an application wouldn't be able to receive one packet at a time
> anymore.
>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>> Again, shouldn't this sort of configuration be a field in the `dev_info`
>> struct rather than having to be special-cased for each driver? Also, must 16
>> be a "magic number" here?
>>> Dmitry Eremin-Solenikov(lumag) wrote:
>>> It looks like this should be fixed inside DPDK rather than here.
>>>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>>>> Presumably these drivers have a way of flushing short bursts? If the
>>>> `min_rx_burst` is 4 and the other side sends an odd number of packets,
>>>> presumably the receiver application isn't left hanging forever waiting for
>>>> the rest of a burst that will never arrive?
>>>>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>>>>> Wouldn't it be simpler (and more extensible) to have `min_rx_burst` as a
>>>>> field in the `dev_info` struct?
>>>>>> nagarahalli wrote
>>>>>> 'min_rx_burst' should be added to the capability as it is a restriction
>>>>>> from the device. The application should adjust the 'num' according to
>>>>>> the capability it reads from the pkt I/O.
https://github.com/Linaro/odp/pull/287#discussion_r149896641
updated_at 2017-11-09 08:54:21
