04/09/2023 10:43, Morten Brørup: > /** Force minimum cache line alignment. */ > #define __rte_cache_min_aligned __rte_aligned(RTE_CACHE_LINE_MIN_SIZE) > > +#define _RTE_CACHE_GUARD_HELPER2(unique) \ > + char cache_guard_ ## unique[RTE_CACHE_LINE_SIZE * > RTE_CACHE_GUARD_LINES] \ > + __rte_cache_aligned > +#define _RTE_CACHE_GUARD_HELPER1(unique) _RTE_CACHE_GUARD_HELPER2(unique)
What is the reason for this intermediate helper macro? > +/** > + * Empty cache lines, to guard against false sharing-like effects > + * on systems with a next-N-lines hardware prefetcher. > + * > + * Use as spacing between data accessed by different lcores, > + * to prevent cache thrashing on hardware with speculative prefetching. > + */ > +#define RTE_CACHE_GUARD _RTE_CACHE_GUARD_HELPER1(__COUNTER__)
