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Date: Tue, 21 Jul 2015 16:09:59 +0100
From: Zoltan Kiss <zoltan.kiss@linaro.org>
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Subject: [dpdk-dev] ixgbe_recv_scattered_pkts_vec split_flags question
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Hi,

I have a question regarding split_flags in this question. It's defined 
as an array of 1 byte unsigned ints:

uint8_t split_flags[RTE_IXGBE_VPMD_RX_BURST] = {0};

RTE_IXGBE_VPMD_RX_BURST is 32, so it will be 32 bytes. Then we cast it 
into a pointer for 4 byte values, and check the first 4 elements of that 
array

const uint32_t *split_fl32 = (uint32_t *)split_flags;
if (rxq->pkt_first_seg == NULL &&
		split_fl32[0] == 0 && split_fl32[1] == 0 &&
		split_fl32[2] == 0 && split_fl32[3] == 0)

So we only check the first half of this 32 byte array. But 
_recv_raw_pkts_vec() seems to use the whole array. Is this a bug or a 
feature? Or am I mistaken in the math somewhere?

Regards,

Zoltan Kiss