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authorEric Dumazet <edumazet@google.com>2016-12-08 22:41:57 +0300
committerDavid S. Miller <davem@davemloft.net>2016-12-10 06:12:21 +0300
commit02ab0d139cff1efc5aa1fb4378c727668334fe97 (patch)
tree7aea980802490b448bedac089074929b9c47d13b
parent6b229cf77d683f634f0edd876c6d1015402303ad (diff)
downloadlinux-02ab0d139cff1efc5aa1fb4378c727668334fe97.tar.xz
udp: udp_rmem_release() should touch sk_rmem_alloc later
In flood situations, keeping sk_rmem_alloc at a high value prevents producers from touching the socket. It makes sense to lower sk_rmem_alloc only at the end of udp_rmem_release() after the thread draining receive queue in udp_recvmsg() finished the writes to sk_forward_alloc. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/ipv4/udp.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 5a38faa12cde..9ca279b130d5 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1191,13 +1191,14 @@ static void udp_rmem_release(struct sock *sk, int size, int partial)
}
up->forward_deficit = 0;
- atomic_sub(size, &sk->sk_rmem_alloc);
sk->sk_forward_alloc += size;
amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1);
sk->sk_forward_alloc -= amt;
if (amt)
__sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT);
+
+ atomic_sub(size, &sk->sk_rmem_alloc);
}
/* Note: called with sk_receive_queue.lock held.