Matias Elo(matiaselo) replied on github web page:
platform/linux-generic/pktio/loop.c
@@ -177,13 +177,15 @@ static int loopback_send(pktio_entry_t *pktio_entry, int
index ODP_UNUSED,
int i;
int ret;
uint32_t bytes = 0;
+ uint32_t out_octets_tbl[len];
if (odp_unlikely(len > QUEUE_MULTI_MAX))
len = QUEUE_MULTI_MAX;
for (i = 0; i < len; ++i) {
hdr_tbl[i] = packet_to_buf_hdr(pkt_tbl[i]);
bytes += odp_packet_len(pkt_tbl[i]);
+ out_octets_tbl[i] = bytes;
Comment:
This array is used to update `stats.out_octets` correctly if `enq_multi()`
fails to enqueue all packets. Without it a second for loop would be required
inside `if (ret > 0)` clause below.
> Matias Elo(matiaselo) wrote:
> The most specific error type an application can see is
> odp_packet_has_l2_error(), so it cannot trust packet contents anyway.
>> Matias Elo(matiaselo) wrote:
>> Will fix.
>>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>>> The error bit simply says the packet was truncated to max length. Perhaps
>>> the application is only interested in the first few bytes of a packet?
>>>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>>>> `ring->frame_num = next_frame(first_frame_num + nb_tx - 1, frame_count);`
>>>> is an alternative here.
>>>>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>>>>> Since `ring->rd_num` is a power of two, is the concern here that the `%`
>>>>> operator might result in a division if the compiler doesn't know that
>>>>> it's a power of two? In that case:
>>>>> ```
>>>>> return ++cur_frame & (frame_count - 1);
>>>>> ```
>>>>> solves that problem and avoids conditional branching.
>>>>>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>>>>>> If we're cleaning up, might as well delete that extraneous `+` in the
>>>>>> above line: `TPACKET_ALIGNMENT + + (pz - 1)) & (-pz);` I'm surprised the
>>>>>> compiler doesn't flag that since it's normally so picky about issuing
>>>>>> warnings.
>>>>>>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>>>>>>> Not sure I understand what `out_octets_tbl` is accumulating here. If
>>>>>>> I'm sending three 100 byte packets this will set `out_octets_tbl[0]` to
>>>>>>> 100, `out_octets_tbl[1]` to 200, and `out_octets_tbl[2]` to 300.
>>>>>>>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>>>>>>>> Since you're doing miscellaneous cleanups anyway, perhaps changing
>>>>>>>> `len` to `num` here should be considered? `len` is confusing since it
>>>>>>>> doesn't represent packet length.
>>>>>>>>> Matias Elo(matiaselo) wrote:
>>>>>>>>> The odp_pktin_maxlen() API states:
>>>>>>>>> > Maximum frame length in bytes that the packet IO interface can
>>>>>>>>> > receive.
>>>>>>>>>
>>>>>>>>> I interpret this so that the application shouln't see packets which
>>>>>>>>> exceed pktin max length.
>>>>>>>>>
>>>>>>>>>> muvarov wrote
>>>>>>>>>> same here.
>>>>>>>>>>> muvarov wrote
>>>>>>>>>>> maybe to just set error bit and deliver this packet to application?
https://github.com/Linaro/odp/pull/397#discussion_r162326632
updated_at 2018-01-18 12:26:02
