Commit 18f02545 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by David S. Miller
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[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: default avatarIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5b3c9882
......@@ -231,6 +231,9 @@ enum
LINUX_MIB_TCPABORTONLINGER, /* TCPAbortOnLinger */
LINUX_MIB_TCPABORTFAILED, /* TCPAbortFailed */
LINUX_MIB_TCPMEMORYPRESSURES, /* TCPMemoryPressures */
LINUX_MIB_TCPSACKDISCARD, /* TCPSACKDiscard */
LINUX_MIB_TCPDSACKIGNOREDOLD, /* TCPSACKIgnoredOld */
LINUX_MIB_TCPDSACKIGNOREDNOUNDO, /* TCPSACKIgnoredNoUndo */
__LINUX_MIB_MAX
};
......
......@@ -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
};
......
......@@ -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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