linux-kernel - [PATCH net-next 2/7] rxrpc: Switch to Congestion Avoidance mode at cwnd==ssthresh

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

Message-ID: <147527162554.28826.2723484388550024625.stgit@warthog.procyon.org.uk>
Date:   Fri, 30 Sep 2016 22:40:25 +0100
From:   David Howells <dhowells@...hat.com>
To:     netdev@...r.kernel.org
Cc:     dhowells@...hat.com, linux-afs@...ts.infradead.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH net-next 2/7] rxrpc: Switch to Congestion Avoidance mode at
 cwnd==ssthresh

Switch to Congestion Avoidance mode at cwnd == ssthresh rather than relying
on cwnd getting incremented beyond ssthresh and the window size, the mode
being shifted and then cwnd being corrected.

We need to make sure we switch into CA mode so that we stop marking every
packet for ACK.

Signed-off-by: David Howells <dhowells@...hat.com>
---

 net/rxrpc/input.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 1461d30583c9..21746f0f7ae0 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -57,7 +57,7 @@ static void rxrpc_congestion_management(struct rxrpc_call *call,
 		call->cong_ssthresh = max_t(unsigned int,
 					    summary->flight_size / 2, 2);
 		cwnd = 1;
-		if (cwnd > call->cong_ssthresh &&
+		if (cwnd >= call->cong_ssthresh &&
 		    call->cong_mode == RXRPC_CALL_SLOW_START) {
 			call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
 			call->cong_tstamp = skb->tstamp;
@@ -82,7 +82,7 @@ static void rxrpc_congestion_management(struct rxrpc_call *call,
 			goto packet_loss_detected;
 		if (summary->cumulative_acks > 0)
 			cwnd += 1;
-		if (cwnd > call->cong_ssthresh) {
+		if (cwnd >= call->cong_ssthresh) {
 			call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
 			call->cong_tstamp = skb->tstamp;
 		}
@@ -161,7 +161,7 @@ resume_normality:
 	call->cong_dup_acks = 0;
 	call->cong_extra = 0;
 	call->cong_tstamp = skb->tstamp;
-	if (cwnd <= call->cong_ssthresh)
+	if (cwnd < call->cong_ssthresh)
 		call->cong_mode = RXRPC_CALL_SLOW_START;
 	else
 		call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;