From 5861f8e58dd84fc34b691c2e8d4824dea68c360e Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ilpo=20J=C3=A4rvinen?= Date: Sat, 14 Mar 2009 14:23:01 +0000 Subject: [PATCH] tcp: remove pointless .dsack/.num_sacks code MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit In the pure assignment case, the earlier zeroing is still in effect. David S. Miller raised concerns if the ifs are there to avoid dirtying cachelines. I came to these conclusions: > We'll be dirty it anyway (now that I check), the first "real" statement > in tcp_rcv_established is: > > tp->rx_opt.saw_tstamp = 0; > > ...that'll land on the same dword. :-/ > > I suppose the blocks are there just because they had more complexity > inside when they had to calculate the eff_sacks too (maybe it would > have been better to just remove them in that drop-patch so you would > have had less head-ache :-)). Signed-off-by: Ilpo Järvinen Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 7 ++----- net/ipv4/tcp_output.c | 3 +-- 2 files changed, 3 insertions(+), 7 deletions(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 5ecd7aa25979..cd39d1d02dc3 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4248,8 +4248,7 @@ static void tcp_sack_remove(struct tcp_sock *tp) this_sack++; sp++; } - if (num_sacks != tp->rx_opt.num_sacks) - tp->rx_opt.num_sacks = num_sacks; + tp->rx_opt.num_sacks = num_sacks; } /* This one checks to see if we can put data from the @@ -4325,8 +4324,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb) TCP_ECN_accept_cwr(tp, skb); - if (tp->rx_opt.dsack) - tp->rx_opt.dsack = 0; + tp->rx_opt.dsack = 0; /* Queue data for delivery to the user. * Packets in sequence go to the receive queue. @@ -4445,7 +4443,6 @@ drop: /* Initial out of order segment, build 1 SACK. */ if (tcp_is_sack(tp)) { tp->rx_opt.num_sacks = 1; - tp->rx_opt.dsack = 0; tp->selective_acks[0].start_seq = TCP_SKB_CB(skb)->seq; tp->selective_acks[0].end_seq = TCP_SKB_CB(skb)->end_seq; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index eb285befdf3b..325658039139 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -441,8 +441,7 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp, *ptr++ = htonl(sp[this_sack].end_seq); } - if (tp->rx_opt.dsack) - tp->rx_opt.dsack = 0; + tp->rx_opt.dsack = 0; } } -- 2.20.1