* Andi Kleen : Moved open_request checking here
* and process RSTs for open_requests.
* Andi Kleen : Better prune_queue, and other fixes.
- * Andrey Savochkin: Fix RTT measurements in the presnce of
+ * Andrey Savochkin: Fix RTT measurements in the presence of
* timestamps.
* Andrey Savochkin: Check sequence numbers correctly when
* removing SACKs due to in sequence incoming
* of receiver window. Check #2.
*
* The scheme does not work when sender sends good segments opening
- * window and then starts to feed us spagetti. But it should work
+ * window and then starts to feed us spaghetti. But it should work
* in common situations. Otherwise, we have to rely on queue collapsing.
*/
{
/* Optimize this! */
int truesize = tcp_win_from_space(skb->truesize)/2;
- int window = tcp_full_space(sk)/2;
+ int window = tcp_win_from_space(sysctl_tcp_rmem[2])/2;
while (tp->rcv_ssthresh <= window) {
if (truesize <= skb->len)
int rcvmem = tp->advmss + MAX_TCP_HEADER + 16 + sizeof(struct sk_buff);
/* Try to select rcvbuf so that 4 mss-sized segments
- * will fit to window and correspoding skbs will fit to our rcvbuf.
+ * will fit to window and corresponding skbs will fit to our rcvbuf.
* (was 3; 4 is minimum to allow fast retransmit to work.)
*/
while (tcp_win_from_space(rcvmem) < tp->advmss)
sk->sk_rcvbuf = min(4 * rcvmem, sysctl_tcp_rmem[2]);
}
-/* 4. Try to fixup all. It is made iimediately after connection enters
+/* 4. Try to fixup all. It is made immediately after connection enters
* established state.
*/
static void tcp_init_buffer_space(struct sock *sk)
static void tcp_clamp_window(struct sock *sk, struct tcp_sock *tp)
{
struct inet_connection_sock *icsk = inet_csk(sk);
- struct sk_buff *skb;
- unsigned int app_win = tp->rcv_nxt - tp->copied_seq;
- int ofo_win = 0;
icsk->icsk_ack.quick = 0;
- skb_queue_walk(&tp->out_of_order_queue, skb) {
- ofo_win += skb->len;
- }
-
- /* If overcommit is due to out of order segments,
- * do not clamp window. Try to expand rcvbuf instead.
- */
- if (ofo_win) {
- if (sk->sk_rcvbuf < sysctl_tcp_rmem[2] &&
- !(sk->sk_userlocks & SOCK_RCVBUF_LOCK) &&
- !tcp_memory_pressure &&
- atomic_read(&tcp_memory_allocated) < sysctl_tcp_mem[0])
- sk->sk_rcvbuf = min(atomic_read(&sk->sk_rmem_alloc),
- sysctl_tcp_rmem[2]);
+ if (sk->sk_rcvbuf < sysctl_tcp_rmem[2] &&
+ !(sk->sk_userlocks & SOCK_RCVBUF_LOCK) &&
+ !tcp_memory_pressure &&
+ atomic_read(&tcp_memory_allocated) < sysctl_tcp_mem[0]) {
+ sk->sk_rcvbuf = min(atomic_read(&sk->sk_rmem_alloc),
+ sysctl_tcp_rmem[2]);
}
- if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) {
- app_win += ofo_win;
- if (atomic_read(&sk->sk_rmem_alloc) >= 2 * sk->sk_rcvbuf)
- app_win >>= 1;
- if (app_win > icsk->icsk_ack.rcv_mss)
- app_win -= icsk->icsk_ack.rcv_mss;
- app_win = max(app_win, 2U*tp->advmss);
-
+ if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf)
tp->rcv_ssthresh = min(tp->window_clamp, 2U*tp->advmss);
- }
}
/* Receiver "autotuning" code.
* are stalled on filesystem I/O.
*
* Also, since we are only going for a minimum in the
- * non-timestamp case, we do not smoothe things out
- * else with timestamps disabled convergance takes too
+ * non-timestamp case, we do not smooth things out
+ * else with timestamps disabled convergence takes too
* long.
*/
if (!win_dep) {
} else if (m < new_sample)
new_sample = m << 3;
} else {
- /* No previous mesaure. */
+ /* No previous measure. */
new_sample = m << 3;
}
if (icsk->icsk_ack.ato > icsk->icsk_rto)
icsk->icsk_ack.ato = icsk->icsk_rto;
} else if (m > icsk->icsk_rto) {
- /* Too long gap. Apparently sender falled to
+ /* Too long gap. Apparently sender failed to
* restart window, so that we send ACKs quickly.
*/
tcp_incr_quickack(sk);
*
* Funny. This algorithm seems to be very broken.
* These formulae increase RTO, when it should be decreased, increase
- * too slowly, when it should be incresed fastly, decrease too fastly
+ * too slowly, when it should be increased quickly, decrease too quickly
* etc. I guess in BSD RTO takes ONE value, so that it is absolutely
* does not matter how to _calculate_ it. Seems, it was trap
* that VJ failed to avoid. 8)
* at least by solaris and freebsd. "Erratic ACKs" has _nothing_
* to do with delayed acks, because at cwnd>2 true delack timeout
* is invisible. Actually, Linux-2.4 also generates erratic
- * ACKs in some curcumstances.
+ * ACKs in some circumstances.
*/
inet_csk(sk)->icsk_rto = (tp->srtt >> 3) + tp->rttvar;
/* 2. Fixups made earlier cannot be right.
* If we do not estimate RTO correctly without them,
* all the algo is pure shit and should be replaced
- * with correct one. It is exaclty, which we pretend to do.
+ * with correct one. It is exactly, which we pretend to do.
*/
}
* to make it more realistic.
*
* A bit of theory. RTT is time passed after "normal" sized packet
- * is sent until it is ACKed. In normal curcumstances sending small
+ * is sent until it is ACKed. In normal circumstances sending small
* packets force peer to delay ACKs and calculation is correct too.
* The algorithm is adaptive and, provided we follow specs, it
* NEVER underestimate RTT. BUT! If peer tries to make some clever
int prior_fackets;
u32 lost_retrans = 0;
int flag = 0;
+ int dup_sack = 0;
int i;
if (!tp->sacked_out)
tp->fackets_out = 0;
prior_fackets = tp->fackets_out;
- for (i=0; i<num_sacks; i++, sp++) {
- struct sk_buff *skb;
- __u32 start_seq = ntohl(sp->start_seq);
- __u32 end_seq = ntohl(sp->end_seq);
- int fack_count = 0;
- int dup_sack = 0;
+ /* SACK fastpath:
+ * if the only SACK change is the increase of the end_seq of
+ * the first block then only apply that SACK block
+ * and use retrans queue hinting otherwise slowpath */
+ flag = 1;
+ for (i = 0; i< num_sacks; i++) {
+ __u32 start_seq = ntohl(sp[i].start_seq);
+ __u32 end_seq = ntohl(sp[i].end_seq);
+
+ if (i == 0){
+ if (tp->recv_sack_cache[i].start_seq != start_seq)
+ flag = 0;
+ } else {
+ if ((tp->recv_sack_cache[i].start_seq != start_seq) ||
+ (tp->recv_sack_cache[i].end_seq != end_seq))
+ flag = 0;
+ }
+ tp->recv_sack_cache[i].start_seq = start_seq;
+ tp->recv_sack_cache[i].end_seq = end_seq;
/* Check for D-SACK. */
if (i == 0) {
if (before(ack, prior_snd_una - tp->max_window))
return 0;
}
+ }
+
+ if (flag)
+ num_sacks = 1;
+ else {
+ int j;
+ tp->fastpath_skb_hint = NULL;
+
+ /* order SACK blocks to allow in order walk of the retrans queue */
+ for (i = num_sacks-1; i > 0; i--) {
+ for (j = 0; j < i; j++){
+ if (after(ntohl(sp[j].start_seq),
+ ntohl(sp[j+1].start_seq))){
+ sp[j].start_seq = htonl(tp->recv_sack_cache[j+1].start_seq);
+ sp[j].end_seq = htonl(tp->recv_sack_cache[j+1].end_seq);
+ sp[j+1].start_seq = htonl(tp->recv_sack_cache[j].start_seq);
+ sp[j+1].end_seq = htonl(tp->recv_sack_cache[j].end_seq);
+ }
+
+ }
+ }
+ }
+
+ /* clear flag as used for different purpose in following code */
+ flag = 0;
+
+ for (i=0; i<num_sacks; i++, sp++) {
+ struct sk_buff *skb;
+ __u32 start_seq = ntohl(sp->start_seq);
+ __u32 end_seq = ntohl(sp->end_seq);
+ int fack_count;
+
+ /* Use SACK fastpath hint if valid */
+ if (tp->fastpath_skb_hint) {
+ skb = tp->fastpath_skb_hint;
+ fack_count = tp->fastpath_cnt_hint;
+ } else {
+ skb = sk->sk_write_queue.next;
+ fack_count = 0;
+ }
/* Event "B" in the comment above. */
if (after(end_seq, tp->high_seq))
flag |= FLAG_DATA_LOST;
- sk_stream_for_retrans_queue(skb, sk) {
+ sk_stream_for_retrans_queue_from(skb, sk) {
int in_sack, pcount;
u8 sacked;
+ tp->fastpath_skb_hint = skb;
+ tp->fastpath_cnt_hint = fack_count;
+
/* The retransmission queue is always in order, so
* we can short-circuit the walk early.
*/
TCP_SKB_CB(skb)->sacked &= ~(TCPCB_LOST|TCPCB_SACKED_RETRANS);
tp->lost_out -= tcp_skb_pcount(skb);
tp->retrans_out -= tcp_skb_pcount(skb);
+
+ /* clear lost hint */
+ tp->retransmit_skb_hint = NULL;
}
} else {
/* New sack for not retransmitted frame,
if (sacked & TCPCB_LOST) {
TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
tp->lost_out -= tcp_skb_pcount(skb);
+
+ /* clear lost hint */
+ tp->retransmit_skb_hint = NULL;
}
}
(TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_RETRANS)) {
TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
tp->retrans_out -= tcp_skb_pcount(skb);
+ tp->retransmit_skb_hint = NULL;
}
}
}
TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
tp->retrans_out -= tcp_skb_pcount(skb);
+ /* clear lost hint */
+ tp->retransmit_skb_hint = NULL;
+
if (!(TCP_SKB_CB(skb)->sacked&(TCPCB_LOST|TCPCB_SACKED_ACKED))) {
tp->lost_out += tcp_skb_pcount(skb);
TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
tcp_set_ca_state(sk, TCP_CA_Loss);
tp->high_seq = tp->frto_highmark;
TCP_ECN_queue_cwr(tp);
+
+ clear_all_retrans_hints(tp);
}
void tcp_clear_retrans(struct tcp_sock *tp)
tcp_set_ca_state(sk, TCP_CA_Loss);
tp->high_seq = tp->snd_nxt;
TCP_ECN_queue_cwr(tp);
+
+ clear_all_retrans_hints(tp);
}
static int tcp_check_sack_reneging(struct sock *sk)
int packets, u32 high_seq)
{
struct sk_buff *skb;
- int cnt = packets;
+ int cnt;
- BUG_TRAP(cnt <= tp->packets_out);
+ BUG_TRAP(packets <= tp->packets_out);
+ if (tp->lost_skb_hint) {
+ skb = tp->lost_skb_hint;
+ cnt = tp->lost_cnt_hint;
+ } else {
+ skb = sk->sk_write_queue.next;
+ cnt = 0;
+ }
- sk_stream_for_retrans_queue(skb, sk) {
- cnt -= tcp_skb_pcount(skb);
- if (cnt < 0 || after(TCP_SKB_CB(skb)->end_seq, high_seq))
+ sk_stream_for_retrans_queue_from(skb, sk) {
+ /* TODO: do this better */
+ /* this is not the most efficient way to do this... */
+ tp->lost_skb_hint = skb;
+ tp->lost_cnt_hint = cnt;
+ cnt += tcp_skb_pcount(skb);
+ if (cnt > packets || after(TCP_SKB_CB(skb)->end_seq, high_seq))
break;
if (!(TCP_SKB_CB(skb)->sacked&TCPCB_TAGBITS)) {
TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
tp->lost_out += tcp_skb_pcount(skb);
+
+ /* clear xmit_retransmit_queue hints
+ * if this is beyond hint */
+ if(tp->retransmit_skb_hint != NULL &&
+ before(TCP_SKB_CB(skb)->seq,
+ TCP_SKB_CB(tp->retransmit_skb_hint)->seq)) {
+
+ tp->retransmit_skb_hint = NULL;
+ }
}
}
tcp_sync_left_out(tp);
if (tcp_head_timedout(sk, tp)) {
struct sk_buff *skb;
- sk_stream_for_retrans_queue(skb, sk) {
- if (tcp_skb_timedout(sk, skb) &&
- !(TCP_SKB_CB(skb)->sacked&TCPCB_TAGBITS)) {
+ skb = tp->scoreboard_skb_hint ? tp->scoreboard_skb_hint
+ : sk->sk_write_queue.next;
+
+ sk_stream_for_retrans_queue_from(skb, sk) {
+ if (!tcp_skb_timedout(sk, skb))
+ break;
+
+ if (!(TCP_SKB_CB(skb)->sacked&TCPCB_TAGBITS)) {
TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
tp->lost_out += tcp_skb_pcount(skb);
+
+ /* clear xmit_retrans hint */
+ if (tp->retransmit_skb_hint &&
+ before(TCP_SKB_CB(skb)->seq,
+ TCP_SKB_CB(tp->retransmit_skb_hint)->seq))
+
+ tp->retransmit_skb_hint = NULL;
}
}
+
+ tp->scoreboard_skb_hint = skb;
+
tcp_sync_left_out(tp);
}
}
}
tcp_moderate_cwnd(tp);
tp->snd_cwnd_stamp = tcp_time_stamp;
+
+ /* There is something screwy going on with the retrans hints after
+ an undo */
+ clear_all_retrans_hints(tp);
}
static inline int tcp_may_undo(struct tcp_sock *tp)
sk_stream_for_retrans_queue(skb, sk) {
TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
}
+
+ clear_all_retrans_hints(tp);
+
DBGUNDO(sk, tp, "partial loss");
tp->lost_out = 0;
tp->left_out = tp->sacked_out;
}
/* Read draft-ietf-tcplw-high-performance before mucking
- * with this code. (Superceeds RFC1323)
+ * with this code. (Supersedes RFC1323)
*/
static void tcp_ack_saw_tstamp(struct sock *sk, int flag)
{
* 1998/04/10 Andrey V. Savochkin <saw@msu.ru>
*
* Changed: reset backoff as soon as we see the first valid sample.
- * If we do not, we get strongly overstimated rto. With timestamps
+ * If we do not, we get strongly overestimated rto. With timestamps
* samples are accepted even from very old segments: f.e., when rtt=1
* increases to 8, we retransmit 5 times and after 8 seconds delayed
* answer arrives rto becomes 120 seconds! If at least one of segments
tcp_packets_out_dec(tp, skb);
__skb_unlink(skb, &sk->sk_write_queue);
sk_stream_free_skb(sk, skb);
+ clear_all_retrans_hints(tp);
}
if (acked&FLAG_ACKED) {
}
/* F-RTO affects on two new ACKs following RTO.
- * At latest on third ACK the TCP behavor is back to normal.
+ * At latest on third ACK the TCP behavior is back to normal.
*/
tp->frto_counter = (tp->frto_counter + 1) % 3;
}
tcp_process_frto(sk, prior_snd_una);
if (tcp_ack_is_dubious(sk, flag)) {
- /* Advanve CWND, if state allows this. */
+ /* Advance CWND, if state allows this. */
if ((flag & FLAG_DATA_ACKED) && tcp_may_raise_cwnd(sk, flag))
tcp_cong_avoid(sk, ack, seq_rtt, prior_in_flight, 0);
tcp_fastretrans_alert(sk, prior_snd_una, prior_packets, flag);
{
struct sk_buff *skb;
- /* First, check that queue is collapsable and find
+ /* First, check that queue is collapsible and find
* the point where collapsing can be useful. */
for (skb = head; skb != tail; ) {
/* No new bits? It is possible on ofo queue. */
/*
* This routine is only called when we have urgent data
- * signalled. Its the 'slow' part of tcp_urg. It could be
+ * signaled. Its the 'slow' part of tcp_urg. It could be
* moved inline now as tcp_urg is only called from one
* place. We handle URGent data wrong. We have to - as
* BSD still doesn't use the correction from RFC961.
* urgent. To do this requires some care. We cannot just ignore
* tp->copied_seq since we would read the last urgent byte again
* as data, nor can we alter copied_seq until this data arrives
- * or we break the sematics of SIOCATMARK (and thus sockatmark())
+ * or we break the semantics of SIOCATMARK (and thus sockatmark())
*
* NOTE. Double Dutch. Rendering to plain English: author of comment
* above did something sort of send("A", MSG_OOB); send("B", MSG_OOB);
tp->rx_opt.saw_tstamp = 0;
/* pred_flags is 0xS?10 << 16 + snd_wnd
- * if header_predition is to be made
+ * if header_prediction is to be made
* 'S' will always be tp->tcp_header_len >> 2
* '?' will be 0 for the fast path, otherwise pred_flags is 0 to
* turn it off (when there are holes in the receive
projects / powerpc.git / blobdiff