net_sched: fix ip_tos2prio
authorDan Siemon <dan@coverfire.com>
Tue, 15 Mar 2011 13:56:07 +0000 (13:56 +0000)
committerDavid S. Miller <davem@davemloft.net>
Wed, 16 Mar 2011 01:53:54 +0000 (18:53 -0700)
ECN support incorrectly maps ECN BESTEFFORT packets to TC_PRIO_FILLER
(1) instead of TC_PRIO_BESTEFFORT (0)

This means ECN enabled flows are placed in pfifo_fast/prio low priority
band, giving ECN enabled flows [ECT(0) and CE codepoints] higher drop
probabilities.

This is rather unfortunate, given we would like ECN being more widely
used.

Ref : http://www.coverfire.com/archives/2011/03/13/pfifo_fast-and-ecn/

Signed-off-by: Dan Siemon <dan@coverfire.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Dave Täht <d@taht.net>
Cc: Jonathan Morton <chromatix99@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/route.c

index 209989cf7d1bf1e68fffb2f09c2a852701e50c1c..870b5182ddd8a88c71cd7b4399779a850372cdfa 100644 (file)
@@ -204,7 +204,7 @@ static struct dst_ops ipv4_dst_ops = {
 
 const __u8 ip_tos2prio[16] = {
        TC_PRIO_BESTEFFORT,
-       ECN_OR_COST(FILLER),
+       ECN_OR_COST(BESTEFFORT),
        TC_PRIO_BESTEFFORT,
        ECN_OR_COST(BESTEFFORT),
        TC_PRIO_BULK,