From ae19c54866450f6c6f79223ca7d37965859a54e1 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 30 Apr 2010 22:41:09 -0400 Subject: sctp: remove 'resent' bit from the chunk The 'resent' bit is used to make sure that we don't update rto estimate based on retransmitted chunks. However, we already have the 'rto_pending' bit that we test when need to update rto, so 'resent' bit is just extra. Additionally, we currently have a bug in that we always set a 'resent' bit and thus rto estimate is only updated by Heartbeats. Signed-off-by: Vlad Yasevich --- include/net/sctp/structs.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'include/net/sctp/structs.h') diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index ff3017744711..03deffb1886b 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -757,7 +757,6 @@ struct sctp_chunk { #define SCTP_NEED_FRTX 0x1 #define SCTP_DONT_FRTX 0x2 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */ - resent:1, /* Has this chunk ever been resent. */ has_tsn:1, /* Does this chunk have a TSN yet? */ has_ssn:1, /* Does this chunk have a SSN yet? */ singleton:1, /* Only chunk in the packet? */ @@ -1065,7 +1064,7 @@ void sctp_transport_route(struct sctp_transport *, union sctp_addr *, struct sctp_sock *); void sctp_transport_pmtu(struct sctp_transport *); void sctp_transport_free(struct sctp_transport *); -void sctp_transport_reset_timers(struct sctp_transport *, int); +void sctp_transport_reset_timers(struct sctp_transport *); void sctp_transport_hold(struct sctp_transport *); void sctp_transport_put(struct sctp_transport *); void sctp_transport_update_rto(struct sctp_transport *, __u32); -- cgit v1.2.3 From c0058a35aacc79406e867ec33c5cb75624fd5860 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 30 Apr 2010 22:41:09 -0400 Subject: sctp: Save some room in the sctp_transport by using bitfields Saves some room in the sctp_transport structure. Signed-off-by: Vlad Yasevich --- include/net/sctp/structs.h | 49 +++++++++++++++++++++++++--------------------- 1 file changed, 27 insertions(+), 22 deletions(-) (limited to 'include/net/sctp/structs.h') diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 03deffb1886b..9072dd67d8ad 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -877,7 +877,33 @@ struct sctp_transport { /* Reference counting. */ atomic_t refcnt; - int dead; + int dead:1, + /* RTO-Pending : A flag used to track if one of the DATA + * chunks sent to this address is currently being + * used to compute a RTT. If this flag is 0, + * the next DATA chunk sent to this destination + * should be used to compute a RTT and this flag + * should be set. Every time the RTT + * calculation completes (i.e. the DATA chunk + * is SACK'd) clear this flag. + */ + rto_pending:1, + + /* + * hb_sent : a flag that signals that we have a pending + * heartbeat. + */ + hb_sent:1, + + /* Flag to track the current fast recovery state */ + fast_recovery:1, + + /* Is the Path MTU update pending on this tranport */ + pmtu_pending:1, + + /* Is this structure kfree()able? */ + malloced:1; + /* This is the peer's IP address and port. */ union sctp_addr ipaddr; @@ -907,22 +933,6 @@ struct sctp_transport { /* SRTT : The current smoothed round trip time. */ __u32 srtt; - /* RTO-Pending : A flag used to track if one of the DATA - * chunks sent to this address is currently being - * used to compute a RTT. If this flag is 0, - * the next DATA chunk sent to this destination - * should be used to compute a RTT and this flag - * should be set. Every time the RTT - * calculation completes (i.e. the DATA chunk - * is SACK'd) clear this flag. - * hb_sent : a flag that signals that we have a pending heartbeat. - */ - __u8 rto_pending; - __u8 hb_sent; - - /* Flag to track the current fast recovery state */ - __u8 fast_recovery; - /* * These are the congestion stats. */ @@ -975,9 +985,6 @@ struct sctp_transport { */ __u16 pathmaxrxt; - /* is the Path MTU update pending on this tranport */ - __u8 pmtu_pending; - /* PMTU : The current known path MTU. */ __u32 pathmtu; @@ -1021,8 +1028,6 @@ struct sctp_transport { /* This is the list of transports that have chunks to send. */ struct list_head send_ready; - int malloced; /* Is this structure kfree()able? */ - /* State information saved for SFR_CACC algorithm. The key * idea in SFR_CACC is to maintain state at the sender on a * per-destination basis when a changeover happens. -- cgit v1.2.3 From cf9b4812e18aab6f86ff998bd7425a9e823269c3 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 30 Apr 2010 22:41:10 -0400 Subject: sctp: fast recovery algorithm is per association. SCTP fast recovery algorithm really applies per association and impacts all transports. Signed-off-by: Vlad Yasevich --- include/net/sctp/structs.h | 12 ++++++------ net/sctp/transport.c | 32 +++++++++++++++++--------------- 2 files changed, 23 insertions(+), 21 deletions(-) (limited to 'include/net/sctp/structs.h') diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 9072dd67d8ad..d463296d9f79 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -895,9 +895,6 @@ struct sctp_transport { */ hb_sent:1, - /* Flag to track the current fast recovery state */ - fast_recovery:1, - /* Is the Path MTU update pending on this tranport */ pmtu_pending:1, @@ -952,9 +949,6 @@ struct sctp_transport { __u32 burst_limited; /* Holds old cwnd when max.burst is applied */ - /* TSN marking the fast recovery exit point */ - __u32 fast_recovery_exit; - /* Destination */ struct dst_entry *dst; /* Source address. */ @@ -1723,6 +1717,12 @@ struct sctp_association { /* Highest TSN that is acknowledged by incoming SACKs. */ __u32 highest_sacked; + /* TSN marking the fast recovery exit point */ + __u32 fast_recovery_exit; + + /* Flag to track the current fast recovery state */ + __u8 fast_recovery; + /* The number of unacknowledged data chunks. Reported through * the SCTP_STATUS sockopt. */ diff --git a/net/sctp/transport.c b/net/sctp/transport.c index 854228bf3f34..fccf4947aff1 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -378,15 +378,16 @@ void sctp_transport_update_rto(struct sctp_transport *tp, __u32 rtt) void sctp_transport_raise_cwnd(struct sctp_transport *transport, __u32 sack_ctsn, __u32 bytes_acked) { + struct sctp_association *asoc = transport->asoc; __u32 cwnd, ssthresh, flight_size, pba, pmtu; cwnd = transport->cwnd; flight_size = transport->flight_size; /* See if we need to exit Fast Recovery first */ - if (transport->fast_recovery && - TSN_lte(transport->fast_recovery_exit, sack_ctsn)) - transport->fast_recovery = 0; + if (asoc->fast_recovery && + TSN_lte(asoc->fast_recovery_exit, sack_ctsn)) + asoc->fast_recovery = 0; /* The appropriate cwnd increase algorithm is performed if, and only * if the cumulative TSN whould advanced and the congestion window is @@ -415,7 +416,7 @@ void sctp_transport_raise_cwnd(struct sctp_transport *transport, * 2) the destination's path MTU. This upper bound protects * against the ACK-Splitting attack outlined in [SAVAGE99]. */ - if (transport->fast_recovery) + if (asoc->fast_recovery) return; if (bytes_acked > pmtu) @@ -466,6 +467,8 @@ void sctp_transport_raise_cwnd(struct sctp_transport *transport, void sctp_transport_lower_cwnd(struct sctp_transport *transport, sctp_lower_cwnd_t reason) { + struct sctp_association *asoc = transport->asoc; + switch (reason) { case SCTP_LOWER_CWND_T3_RTX: /* RFC 2960 Section 7.2.3, sctpimpguide @@ -476,11 +479,11 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport, * partial_bytes_acked = 0 */ transport->ssthresh = max(transport->cwnd/2, - 4*transport->asoc->pathmtu); - transport->cwnd = transport->asoc->pathmtu; + 4*asoc->pathmtu); + transport->cwnd = asoc->pathmtu; - /* T3-rtx also clears fast recovery on the transport */ - transport->fast_recovery = 0; + /* T3-rtx also clears fast recovery */ + asoc->fast_recovery = 0; break; case SCTP_LOWER_CWND_FAST_RTX: @@ -496,15 +499,15 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport, * cwnd = ssthresh * partial_bytes_acked = 0 */ - if (transport->fast_recovery) + if (asoc->fast_recovery) return; /* Mark Fast recovery */ - transport->fast_recovery = 1; - transport->fast_recovery_exit = transport->asoc->next_tsn - 1; + asoc->fast_recovery = 1; + asoc->fast_recovery_exit = asoc->next_tsn - 1; transport->ssthresh = max(transport->cwnd/2, - 4*transport->asoc->pathmtu); + 4*asoc->pathmtu); transport->cwnd = transport->ssthresh; break; @@ -524,7 +527,7 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport, if (time_after(jiffies, transport->last_time_ecne_reduced + transport->rtt)) { transport->ssthresh = max(transport->cwnd/2, - 4*transport->asoc->pathmtu); + 4*asoc->pathmtu); transport->cwnd = transport->ssthresh; transport->last_time_ecne_reduced = jiffies; } @@ -540,7 +543,7 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport, * interval. */ transport->cwnd = max(transport->cwnd/2, - 4*transport->asoc->pathmtu); + 4*asoc->pathmtu); break; } @@ -625,7 +628,6 @@ void sctp_transport_reset(struct sctp_transport *t) t->error_count = 0; t->rto_pending = 0; t->hb_sent = 0; - t->fast_recovery = 0; /* Initialize the state information for SFR-CACC */ t->cacc.changeover_active = 0; -- cgit v1.2.3 From 0e3aef8d09a8c11e3fb83cdcb24b5bc7421b3726 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 30 Apr 2010 22:41:10 -0400 Subject: sctp: Tag messages that can be Nagle delayed at creation. When we create the sctp_datamsg and fragment the user data, we know exactly if we are sending full segments or not and how they might be bundled. During this time, we can mark messages a Nagle capable or not. This makes the check at transmit time much simpler. Signed-off-by: Vlad Yasevich --- include/net/sctp/structs.h | 8 +++----- net/sctp/chunk.c | 4 ++-- net/sctp/output.c | 2 +- 3 files changed, 6 insertions(+), 8 deletions(-) (limited to 'include/net/sctp/structs.h') diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index d463296d9f79..9d44aef365da 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -643,17 +643,15 @@ struct sctp_pf { struct sctp_datamsg { /* Chunks waiting to be submitted to lower layer. */ struct list_head chunks; - /* Chunks that have been transmitted. */ - size_t msg_size; /* Reference counting. */ atomic_t refcnt; /* When is this message no longer interesting to the peer? */ unsigned long expires_at; /* Did the messenge fail to send? */ int send_error; - char send_failed; - /* Control whether chunks from this message can be abandoned. */ - char can_abandon; + u8 send_failed:1, + can_abandon:1, /* can chunks from this message can be abandoned. */ + can_delay; /* should this message be Nagle delayed */ }; struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c index 3eab6db59a37..476caaf100ed 100644 --- a/net/sctp/chunk.c +++ b/net/sctp/chunk.c @@ -58,9 +58,9 @@ static void sctp_datamsg_init(struct sctp_datamsg *msg) msg->send_failed = 0; msg->send_error = 0; msg->can_abandon = 0; + msg->can_delay = 1; msg->expires_at = 0; INIT_LIST_HEAD(&msg->chunks); - msg->msg_size = 0; } /* Allocate and initialize datamsg. */ @@ -157,7 +157,6 @@ static void sctp_datamsg_assign(struct sctp_datamsg *msg, struct sctp_chunk *chu { sctp_datamsg_hold(msg); chunk->msg = msg; - msg->msg_size += chunk->skb->len; } @@ -247,6 +246,7 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, if (msg_len >= first_len) { msg_len -= first_len; whole = 1; + msg->can_delay = 0; } /* How many full sized? How many bytes leftover? */ diff --git a/net/sctp/output.c b/net/sctp/output.c index 35e49b9df4e0..a646681f5acd 100644 --- a/net/sctp/output.c +++ b/net/sctp/output.c @@ -674,7 +674,7 @@ static sctp_xmit_t sctp_packet_can_append_data(struct sctp_packet *packet, * Don't delay large message writes that may have been * fragmeneted into small peices. */ - if ((len < max) && (chunk->msg->msg_size < max)) { + if ((len < max) && chunk->msg->can_delay) { retval = SCTP_XMIT_NAGLE_DELAY; goto finish; } -- cgit v1.2.3