> +void *
> +rte_lcore_var_alloc(size_t size, size_t align)
> +{
> + /* Having the per-lcore buffer size aligned on cache lines
> + * assures as well as having the base pointer aligned on cache
> + * size assures that aligned offsets also translate to alipgned
> + * pointers across all values.
> + */
> + RTE_BUILD_BUG_ON(RTE_MAX_LCORE_VAR % RTE_CACHE_LINE_SIZE != 0);
> + RTE_VERIFY(align <= RTE_CACHE_LINE_SIZE);
> + RTE_VERIFY(size <= RTE_MAX_LCORE_VAR);
> +
> + /* '0' means asking for worst-case alignment requirements */
> + if (align == 0)
> +#ifdef RTE_TOOLCHAIN_MSVC
> + /* MSVC <stddef.h> is missing the max_align_t typedef */
> + align = alignof(double);
> +#else
> + align = alignof(max_align_t);
> +#endif
Do we need worst-case alignment, or does automatic alignment suffice:
/* '0' means asking for automatic alignment requirements */
if (align == 0) {
#ifdef RTE_ARCH_64
align = rte_align64pow2(size);
#else
align = rte_align32pow2(size);
#endif
#ifdef RTE_TOOLCHAIN_MSVC
/* MSVC <stddef.h> is missing the max_align_t typedef */
align = RTE_MIN(align, alignof(double));
#else
align = RTE_MIN(align, alignof(max_align_t));
#endif
}
It will pack small-size lcore variables even tighter.
