netdev - [PATCH net-next] tcp: fix tcp_should_expand_sndbuf() to use tcp_packets_in

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1424457196-3497-1-git-send-email-ncardwell@google.com>
Date:	Fri, 20 Feb 2015 13:33:16 -0500
From:	Neal Cardwell <ncardwell@...gle.com>
To:	David Miller <davem@...emloft.net>
Cc:	netdev@...r.kernel.org, Neal Cardwell <ncardwell@...gle.com>,
	Yuchung Cheng <ycheng@...gle.com>,
	Eric Dumazet <edumazet@...gle.com>,
	Nandita Dukkipati <nanditad@...gle.com>
Subject: [PATCH net-next] tcp: fix tcp_should_expand_sndbuf() to use tcp_packets_in_flight()

tcp_should_expand_sndbuf() does not expand the send buffer if we have
filled the congestion window.

However, it should use tcp_packets_in_flight() instead of
tp->packets_out to make this check.

Testing has established that the difference matters a lot if there are
many SACKed packets, causing a needless performance shortfall.

Signed-off-by: Neal Cardwell <ncardwell@...gle.com>
Signed-off-by: Yuchung Cheng <ycheng@...gle.com>
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
Signed-off-by: Nandita Dukkipati <nanditad@...gle.com>
---
 net/ipv4/tcp_input.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 8fdd27b..fb4cf8b 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4770,7 +4770,7 @@ static bool tcp_should_expand_sndbuf(const struct sock *sk)
 		return false;
 
 	/* If we filled the congestion window, do not expand.  */
-	if (tp->packets_out >= tp->snd_cwnd)
+	if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)
 		return false;
 
 	return true;
-- 
2.2.0.rc0.207.ga3a616c

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html