Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures

Herbert Xu writes:

See sk_stream_mem_schedule in net/core/stream.c:

        /* Under limit. */
        if (atomic_read(sk->sk_prot->memory_allocated) < sk->sk_prot->sysctl_mem[0]) {
                if (*sk->sk_prot->memory_pressure)
                        *sk->sk_prot->memory_pressure = 0;
                return 1;
        }

        /* Over hard limit. */
        if (atomic_read(sk->sk_prot->memory_allocated) > sk->sk_prot->sysctl_mem[2]) {
                sk->sk_prot->enter_memory_pressure();
                goto suppress_allocation;
        }

We don't need to reload sk->sk_prot->memory_allocated here.

Are you sure?  How do you know some other CPU hasn't changed the value
in between?

Paul.