This patch removes a couple of memory barriers from atomic bitops that
showed up on profiles of netperf.
-ben
Signed-off-by: Benjamin LaHaise <[EMAIL PROTECTED]>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 00aa80e..dadc84c 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -682,7 +682,8 @@ int tcp_sendmsg(struct kiocb *iocb, stru
goto out_err;
/* This should be in poll */
- clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
+ if (test_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
+ clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
size_goal = tp->xmit_size_goal;
diff --git a/net/ipv4/netfilter/ip_conntrack_core.c
b/net/ipv4/netfilter/ip_conntrack_core.c
index 84c66db..416e310 100644
--- a/net/ipv4/netfilter/ip_conntrack_core.c
+++ b/net/ipv4/netfilter/ip_conntrack_core.c
@@ -881,7 +881,12 @@ unsigned int ip_conntrack_in(unsigned in
return -ret;
}
- if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
+ /* Use test_bit() first as that avoids a memory barrier on implicite
+ * in test_and_set_bit() on some CPUs. It only gets set once per
+ * connection.
+ */
+ if (set_reply && !test_bit(IPS_SEEN_REPLY_BIT, &ct->status) &&
+ !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
ip_conntrack_event_cache(IPCT_STATUS, *pskb);
return ret;
-
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