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authorIlpo Järvinen <ilpo.jarvinen@helsinki.fi>2007-08-24 22:55:52 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2007-10-10 16:48:30 -0700
commit18f02545a9a16c9a89778b91a162ad16d510bb32 (patch)
tree2b1c67a8168b695630d26216b7dd3be17179ca5c /net/ipv4
parent5b3c98821a8753239aefc1c217409aa3e5c90787 (diff)
downloadop-kernel-dev-18f02545a9a16c9a89778b91a162ad16d510bb32.zip
op-kernel-dev-18f02545a9a16c9a89778b91a162ad16d510bb32.tar.gz
[TCP] MIB: Add counters for discarded SACK blocks
In DSACK case, some events are not extraordinary, such as packet duplication generated DSACK. They can arrive easily below snd_una when undo_marker is not set (TCP being in CA_Open), counting such DSACKs amoung SACK discards will likely just mislead if they occur in some scenario when there are other problems as well. Similarly, excessively delayed packets could cause "normal" DSACKs. Therefore, separate counters are allocated for DSACK events. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/proc.c3
-rw-r--r--net/ipv4/tcp_input.c10
2 files changed, 12 insertions, 1 deletions
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 3b690cf..986d1c8 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -244,6 +244,9 @@ static const struct snmp_mib snmp4_net_list[] = {
SNMP_MIB_ITEM("TCPAbortOnLinger", LINUX_MIB_TCPABORTONLINGER),
SNMP_MIB_ITEM("TCPAbortFailed", LINUX_MIB_TCPABORTFAILED),
SNMP_MIB_ITEM("TCPMemoryPressures", LINUX_MIB_TCPMEMORYPRESSURES),
+ SNMP_MIB_ITEM("TCPSACKDiscard", LINUX_MIB_TCPSACKDISCARD),
+ SNMP_MIB_ITEM("TCPDSACKIgnoredOld", LINUX_MIB_TCPDSACKIGNOREDOLD),
+ SNMP_MIB_ITEM("TCPDSACKIgnoredNoUndo", LINUX_MIB_TCPDSACKIGNOREDNOUNDO),
SNMP_MIB_SENTINEL
};
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index a2364eb..f9e4d7ad6 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1240,8 +1240,16 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
int fack_count;
int dup_sack = (found_dup_sack && (i == first_sack_index));
- if (!tcp_is_sackblock_valid(tp, dup_sack, start_seq, end_seq))
+ if (!tcp_is_sackblock_valid(tp, dup_sack, start_seq, end_seq)) {
+ if (dup_sack) {
+ if (!tp->undo_marker)
+ NET_INC_STATS_BH(LINUX_MIB_TCPDSACKIGNOREDNOUNDO);
+ else
+ NET_INC_STATS_BH(LINUX_MIB_TCPDSACKIGNOREDOLD);
+ } else
+ NET_INC_STATS_BH(LINUX_MIB_TCPSACKDISCARD);
continue;
+ }
skb = cached_skb;
fack_count = cached_fack_count;
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