SEND_MAX_CHUNK
struct sendfilevec sfv[SEND_MAX_CHUNK];
struct ksendfilevec32 sfv32[SEND_MAX_CHUNK];
copy_cnt = MIN(sfvcnt, SEND_MAX_CHUNK);
struct ksendfilevec64 sfv[SEND_MAX_CHUNK];
copy_cnt = MIN(sfvcnt, SEND_MAX_CHUNK);