Do Linux system calls provide acquire/release semantics?

For example, functions like futex_wake/futex_wait, epoll_ctl/epoll_wait, pthread_create provide acquire/release semantics. That's to say, I made some changes before calling futex_wake, and then the woken thread always sees the changes.

My question is

1. does the read/write to eventfd offer acquire/release semantics?
2. is there any documents about this? I have checked the man page and did not find the answer about 1.

see blow code as an example:

initial:
    int g_atomic_val = 0;
    int evfd = eventfd();
    int64_t w_cnt = 1, r_cnt;

thread1:
    /* set some data, then write eventfd */
    g_atomic_val = 1;
    write(evfd, &w_cnt, sizeof(w_cnt));

thread2:
    for (;;) {
        /* polling event fd */
        poll(evfd);
        read(evfd, &r_cnt, sizeof(r_cnt));
        /* Does g_atomic_val always equals to 1? */
        assert(g_atomic_val == 1);
    }