diff mbox

[net-next] tcp: ensure prior synack rtx behavior with small backlogs

Message ID 1444168198.9555.19.camel@edumazet-glaptop2.roam.corp.google.com
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Eric Dumazet Oct. 6, 2015, 9:49 p.m. UTC 
From: Eric Dumazet <edumazet@google.com>

Some applications use a listen() backlog of 1.

Prior kernels were silently enforcing a qlen_log of 4, so that we were
sending up to /proc/sys/net/ipv4/tcp_synack_retries SYNACK messages.

Fixes: ef547f2ac16b ("tcp: remove max_qlen_log")
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv4/inet_connection_sock.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)



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Comments

David Miller Oct. 7, 2015, 12:10 p.m. UTC | #1 
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Tue, 06 Oct 2015 14:49:58 -0700

> From: Eric Dumazet <edumazet@google.com>
> 
> Some applications use a listen() backlog of 1.
> 
> Prior kernels were silently enforcing a qlen_log of 4, so that we were
> sending up to /proc/sys/net/ipv4/tcp_synack_retries SYNACK messages.
> 
> Fixes: ef547f2ac16b ("tcp: remove max_qlen_log")
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Applied, thanks Eric.
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diff mbox

Patch

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 89eedfbd4ad5..514b9e910bd4 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -579,7 +579,7 @@  static void reqsk_timer_handler(unsigned long data)
 	 * ones are about to clog our table.
 	 */
 	qlen = reqsk_queue_len(queue);
-	if ((qlen << 1) > sk_listener->sk_max_ack_backlog) {
+	if ((qlen << 1) > max(8U, sk_listener->sk_max_ack_backlog)) {
 		int young = reqsk_queue_len_young(queue) << 1;
 
 		while (thresh > 2) {