We should define some "well known" packet burst sizes in rte_config.h.
Especially the default packet burst size is interesting; if known at compile time, various drivers and libraries can optimize for it (i.e. special handling for nb_pkts == RTE_PKT_BURST_DEFAULT). It should also be used in DPDK examples and apps, instead of defining MAX_PKT_BURST in each and everyone. Specifically: /** * Default packet burst size. * * Also intended for optimizing packet processing (e.g. by loop unrolling). */ #define RTE_PKT_BURST_DEFAULT 32 /** * Largest packet burst size guaranteed to be supported throughout DPDK. * * Also intended for sizing large temporary arrays of mbufs, e.g. in rte_pktmbuf_free_bulk(). */ #define RTE_PKT_BURST_MAX 512 #define RTE_MEMPOOL_CACHE_MAX_SIZE RTE_PKT_BURST_MAX /** * Smallest packet burst size recommended for latency sensitive applications, when throughput still matters. * * Also intended for sizing small staging arrays of mbufs, e.g. in drivers. * * Note: Corresponds to one CPU cache line of object pointers. * - 8 on most 64 bit architectures, 16 on POWER architecture (ppc_64). * - 16 on all 32 bit architectures. */ #define RTE_PKT_BURST_SMALL (RTE_CACHE_LINE_SIZE / sizeof(void *))
