> +u64 notrace trace_clock_walltime(void)> +{> + u32 remainder;> + return base_walltime.tv_sec + div_u64_rem(> + trace_clock() + base_walltime.tv_nsec,> + NSEC_PER_SEC, &remainder);> +}Why do we need calculate walltime at ring-buffer recordng phase?IOW, Why can't we calculate this at displaing time?