Hi All, I am using DPDK 16.07 for my use. NIC attached to my server is X520, which is using IXGBE Driver. I am a bit confusion about the batching factor and on what basis it is done.
In file "dpdk-16.07/drivers/net/ixgbe/ixgbe_rxtx.h" there are two macros - #define RTE_PMD_IXGBE_TX_MAX_BURST 32 #define RTE_PMD_IXGBE_RX_MAX_BURST 32 which according to me are the batch size at NIC. RTE_PMD_IXGBE_TX_MAX_BURST declares the batch size for transmitting and RTE_PMD_IXGBE_RX_MAX_BURST declares the batch size for receiving. And similarly in the examples, for ex: dpdk-16.07/examples/l2fwd/main.c we are using BURST_SIZE #define MAX_PKT_BURST 32. Now the questions are - Q1: Is my understanding correct about the batch size at NIC and batch size at CPU ? Q2: Why the batch size is 32 and not some other number, shouldn't we decide the batch size depending on the machine configuration ? What are the factors which should be used in deciding the batch size ? I am assuming that latency/per packet is not an issue and we are interested in the throughput. Q3: If first part is not the batch size at NIC, how to add functionality for that ? Thanks Ankit Bhardwaj
