> We should define some "well known" packet burst sizes in rte_config.h. >
A while back we had the same idea, except that it should be platform specific Ex., for CNXK optimal burst size across workloads is 64. Instead of rte_config.h maybe we should have it as a meson option in meson_options.txt with default as 32. That way platforms can also modify it in config/<arch>/meson.build > 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 *))
