tcp: annotate sk->sk_wmem_queued lockless reads

For the sake of tcp_poll(), there are few places where we fetch
sk->sk_wmem_queued while this field can change from IRQ or other cpu.

We need to add READ_ONCE() annotations, and also make sure write
sides use corresponding WRITE_ONCE() to avoid store-tearing.

sk_wmem_queued_add() helper is added so that we can in
the future convert to ADD_ONCE() or equivalent if/when
available.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2019-10-10 20:17:46 -07:00
committed by David S. Miller
parent e292f05e0d
commit ab4e846a82
8 changed files with 24 additions and 19 deletions

View File

@@ -446,7 +446,7 @@ META_COLLECTOR(int_sk_wmem_queued)
*err = -1;
return;
}
dst->value = sk->sk_wmem_queued;
dst->value = READ_ONCE(sk->sk_wmem_queued);
}
META_COLLECTOR(int_sk_fwd_alloc)