From aa6f5ffbdba45aa8e19e5048648fc6c7b25376d3 Mon Sep 17 00:00:00 2001 From: merge Date: Thu, 22 Jan 2009 13:55:32 +0000 Subject: MERGE-via-pending-tracking-hist-MERGE-via-stable-tracking-MERGE-via-mokopatches-tracking-fix-stray-endmenu-patch-1232632040-1232632141 pending-tracking-hist top was MERGE-via-stable-tracking-MERGE-via-mokopatches-tracking-fix-stray-endmenu-patch-1232632040-1232632141 / fdf777a63bcb59e0dfd78bfe2c6242e01f6d4eb9 ... parent commitmessage: From: merge MERGE-via-stable-tracking-hist-MERGE-via-mokopatches-tracking-fix-stray-endmenu-patch-1232632040 stable-tracking-hist top was MERGE-via-mokopatches-tracking-fix-stray-endmenu-patch-1232632040 / 90463bfd2d5a3c8b52f6e6d71024a00e052b0ced ... parent commitmessage: From: merge MERGE-via-mokopatches-tracking-hist-fix-stray-endmenu-patch mokopatches-tracking-hist top was fix-stray-endmenu-patch / 3630e0be570de8057e7f8d2fe501ed353cdf34e6 ... parent commitmessage: From: Andy Green fix-stray-endmenu.patch Signed-off-by: Andy Green --- net/ipv4/tcp_output.c | 230 +++++++++++++++++++++----------------------------- 1 file changed, 94 insertions(+), 136 deletions(-) (limited to 'net/ipv4/tcp_output.c') diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index ba85d883189..557fe16cbfb 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -42,7 +42,7 @@ /* People can turn this off for buggy TCP's found in printers etc. */ int sysctl_tcp_retrans_collapse __read_mostly = 1; -/* People can turn this on to work with those rare, broken TCPs that +/* People can turn this on to work with those rare, broken TCPs that * interpret the window field as a signed quantity. */ int sysctl_tcp_workaround_signed_windows __read_mostly = 0; @@ -484,7 +484,7 @@ static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb, } if (likely(sysctl_tcp_window_scaling)) { opts->ws = tp->rx_opt.rcv_wscale; - if(likely(opts->ws)) + if (likely(opts->ws)) size += TCPOLEN_WSCALE_ALIGNED; } if (likely(sysctl_tcp_sack)) { @@ -526,7 +526,7 @@ static unsigned tcp_synack_options(struct sock *sk, if (likely(ireq->wscale_ok)) { opts->ws = ireq->rcv_wscale; - if(likely(opts->ws)) + if (likely(opts->ws)) size += TCPOLEN_WSCALE_ALIGNED; } if (likely(doing_ts)) { @@ -663,10 +663,14 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, th->urg_ptr = 0; /* The urg_mode check is necessary during a below snd_una win probe */ - if (unlikely(tcp_urg_mode(tp) && - between(tp->snd_up, tcb->seq + 1, tcb->seq + 0xFFFF))) { - th->urg_ptr = htons(tp->snd_up - tcb->seq); - th->urg = 1; + if (unlikely(tcp_urg_mode(tp))) { + if (between(tp->snd_up, tcb->seq + 1, tcb->seq + 0xFFFF)) { + th->urg_ptr = htons(tp->snd_up - tcb->seq); + th->urg = 1; + } else if (after(tcb->seq + 0xFFFF, tp->snd_nxt)) { + th->urg_ptr = 0xFFFF; + th->urg = 1; + } } tcp_options_write((__be32 *)(th + 1), tp, &opts, &md5_hash_location); @@ -1028,10 +1032,6 @@ unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu) /* Compute the current effective MSS, taking SACKs and IP options, * and even PMTU discovery events into account. - * - * LARGESEND note: !tcp_urg_mode is overkill, only frames up to snd_up - * cannot be large. However, taking into account rare use of URG, this - * is not a big flaw. */ unsigned int tcp_current_mss(struct sock *sk, int large_allowed) { @@ -1046,7 +1046,7 @@ unsigned int tcp_current_mss(struct sock *sk, int large_allowed) mss_now = tp->mss_cache; - if (large_allowed && sk_can_gso(sk) && !tcp_urg_mode(tp)) + if (large_allowed && sk_can_gso(sk)) doing_tso = 1; if (dst) { @@ -1172,7 +1172,7 @@ static int tcp_init_tso_segs(struct sock *sk, struct sk_buff *skb, static inline int tcp_minshall_check(const struct tcp_sock *tp) { - return after(tp->snd_sml,tp->snd_una) && + return after(tp->snd_sml, tp->snd_una) && !after(tp->snd_sml, tp->snd_nxt); } @@ -1338,7 +1338,7 @@ static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb) /* Defer for less than two clock ticks. */ if (tp->tso_deferred && - ((jiffies << 1) >> 1) - (tp->tso_deferred >> 1) > 1) + (((u32)jiffies << 1) >> 1) - (tp->tso_deferred >> 1) > 1) goto send_now; in_flight = tcp_packets_in_flight(tp); @@ -1516,10 +1516,15 @@ static int tcp_mtu_probe(struct sock *sk) * send_head. This happens as incoming acks open up the remote * window for us. * + * LARGESEND note: !tcp_urg_mode is overkill, only frames between + * snd_up-64k-mss .. snd_up cannot be large. However, taking into + * account rare use of URG, this is not a big flaw. + * * Returns 1, if no segments are in flight and we have queued segments, but * cannot send anything now because of SWS or another problem. */ -static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle) +static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, + int push_one, gfp_t gfp) { struct tcp_sock *tp = tcp_sk(sk); struct sk_buff *skb; @@ -1527,20 +1532,16 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle) int cwnd_quota; int result; - /* If we are closed, the bytes will have to remain here. - * In time closedown will finish, we empty the write queue and all - * will be happy. - */ - if (unlikely(sk->sk_state == TCP_CLOSE)) - return 0; - sent_pkts = 0; - /* Do MTU probing. */ - if ((result = tcp_mtu_probe(sk)) == 0) { - return 0; - } else if (result > 0) { - sent_pkts = 1; + if (!push_one) { + /* Do MTU probing. */ + result = tcp_mtu_probe(sk); + if (!result) { + return 0; + } else if (result > 0) { + sent_pkts = 1; + } } while ((skb = tcp_send_head(sk))) { @@ -1562,12 +1563,12 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle) nonagle : TCP_NAGLE_PUSH)))) break; } else { - if (tcp_tso_should_defer(sk, skb)) + if (!push_one && tcp_tso_should_defer(sk, skb)) break; } limit = mss_now; - if (tso_segs > 1) + if (tso_segs > 1 && !tcp_urg_mode(tp)) limit = tcp_mss_split_point(sk, skb, mss_now, cwnd_quota); @@ -1577,7 +1578,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle) TCP_SKB_CB(skb)->when = tcp_time_stamp; - if (unlikely(tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC))) + if (unlikely(tcp_transmit_skb(sk, skb, 1, gfp))) break; /* Advance the send_head. This one is sent out. @@ -1587,6 +1588,9 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle) tcp_minshall_update(tp, mss_now, skb); sent_pkts++; + + if (push_one) + break; } if (likely(sent_pkts)) { @@ -1605,10 +1609,18 @@ void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, { struct sk_buff *skb = tcp_send_head(sk); - if (skb) { - if (tcp_write_xmit(sk, cur_mss, nonagle)) - tcp_check_probe_timer(sk); - } + if (!skb) + return; + + /* If we are closed, the bytes will have to remain here. + * In time closedown will finish, we empty the write queue and + * all will be happy. + */ + if (unlikely(sk->sk_state == TCP_CLOSE)) + return; + + if (tcp_write_xmit(sk, cur_mss, nonagle, 0, GFP_ATOMIC)) + tcp_check_probe_timer(sk); } /* Send _single_ skb sitting at the send head. This function requires @@ -1617,36 +1629,10 @@ void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, void tcp_push_one(struct sock *sk, unsigned int mss_now) { struct sk_buff *skb = tcp_send_head(sk); - unsigned int tso_segs, cwnd_quota; BUG_ON(!skb || skb->len < mss_now); - tso_segs = tcp_init_tso_segs(sk, skb, mss_now); - cwnd_quota = tcp_snd_test(sk, skb, mss_now, TCP_NAGLE_PUSH); - - if (likely(cwnd_quota)) { - unsigned int limit; - - BUG_ON(!tso_segs); - - limit = mss_now; - if (tso_segs > 1) - limit = tcp_mss_split_point(sk, skb, mss_now, - cwnd_quota); - - if (skb->len > limit && - unlikely(tso_fragment(sk, skb, limit, mss_now))) - return; - - /* Send it out now. */ - TCP_SKB_CB(skb)->when = tcp_time_stamp; - - if (likely(!tcp_transmit_skb(sk, skb, 1, sk->sk_allocation))) { - tcp_event_new_data_sent(sk, skb); - tcp_cwnd_validate(sk); - return; - } - } + tcp_write_xmit(sk, mss_now, TCP_NAGLE_PUSH, 1, sk->sk_allocation); } /* This function returns the amount that we can raise the @@ -1766,46 +1752,22 @@ u32 __tcp_select_window(struct sock *sk) return window; } -/* Attempt to collapse two adjacent SKB's during retransmission. */ -static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, - int mss_now) +/* Collapses two adjacent SKB's during retransmission. */ +static void tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb) { struct tcp_sock *tp = tcp_sk(sk); struct sk_buff *next_skb = tcp_write_queue_next(sk, skb); int skb_size, next_skb_size; u16 flags; - /* The first test we must make is that neither of these two - * SKB's are still referenced by someone else. - */ - if (skb_cloned(skb) || skb_cloned(next_skb)) - return; - skb_size = skb->len; next_skb_size = next_skb->len; flags = TCP_SKB_CB(skb)->flags; - /* Also punt if next skb has been SACK'd. */ - if (TCP_SKB_CB(next_skb)->sacked & TCPCB_SACKED_ACKED) - return; - - /* Next skb is out of window. */ - if (after(TCP_SKB_CB(next_skb)->end_seq, tcp_wnd_end(tp))) - return; - - /* Punt if not enough space exists in the first SKB for - * the data in the second, or the total combined payload - * would exceed the MSS. - */ - if ((next_skb_size > skb_tailroom(skb)) || - ((skb_size + next_skb_size) > mss_now)) - return; - BUG_ON(tcp_skb_pcount(skb) != 1 || tcp_skb_pcount(next_skb) != 1); tcp_highest_sack_combine(sk, next_skb, skb); - /* Ok. We will be able to collapse the packet. */ tcp_unlink_write_queue(next_skb, sk); skb_copy_from_linear_data(next_skb, skb_put(skb, next_skb_size), @@ -1847,54 +1809,60 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, sk_wmem_free_skb(sk, next_skb); } -/* Do a simple retransmit without using the backoff mechanisms in - * tcp_timer. This is used for path mtu discovery. - * The socket is already locked here. - */ -void tcp_simple_retransmit(struct sock *sk) +static int tcp_can_collapse(struct sock *sk, struct sk_buff *skb) +{ + if (tcp_skb_pcount(skb) > 1) + return 0; + /* TODO: SACK collapsing could be used to remove this condition */ + if (skb_shinfo(skb)->nr_frags != 0) + return 0; + if (skb_cloned(skb)) + return 0; + if (skb == tcp_send_head(sk)) + return 0; + /* Some heurestics for collapsing over SACK'd could be invented */ + if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) + return 0; + + return 1; +} + +static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to, + int space) { - const struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); - struct sk_buff *skb; - unsigned int mss = tcp_current_mss(sk, 0); - u32 prior_lost = tp->lost_out; + struct sk_buff *skb = to, *tmp; + int first = 1; - tcp_for_write_queue(skb, sk) { - if (skb == tcp_send_head(sk)) + if (!sysctl_tcp_retrans_collapse) + return; + if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN) + return; + + tcp_for_write_queue_from_safe(skb, tmp, sk) { + if (!tcp_can_collapse(sk, skb)) break; - if (skb->len > mss && - !(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) { - if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) { - TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS; - tp->retrans_out -= tcp_skb_pcount(skb); - } - tcp_skb_mark_lost_uncond_verify(tp, skb); - } - } - tcp_clear_retrans_hints_partial(tp); + space -= skb->len; - if (prior_lost == tp->lost_out) - return; + if (first) { + first = 0; + continue; + } - if (tcp_is_reno(tp)) - tcp_limit_reno_sacked(tp); + if (space < 0) + break; + /* Punt if not enough space exists in the first SKB for + * the data in the second + */ + if (skb->len > skb_tailroom(to)) + break; - tcp_verify_left_out(tp); + if (after(TCP_SKB_CB(skb)->end_seq, tcp_wnd_end(tp))) + break; - /* Don't muck with the congestion window here. - * Reason is that we do not increase amount of _data_ - * in network, but units changed and effective - * cwnd/ssthresh really reduced now. - */ - if (icsk->icsk_ca_state != TCP_CA_Loss) { - tp->high_seq = tp->snd_nxt; - tp->snd_ssthresh = tcp_current_ssthresh(sk); - tp->prior_ssthresh = 0; - tp->undo_marker = 0; - tcp_set_ca_state(sk, TCP_CA_Loss); + tcp_collapse_retrans(sk, to); } - tcp_xmit_retransmit_queue(sk); } /* This retransmits one SKB. Policy decisions and retransmit queue @@ -1946,17 +1914,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb) return -ENOMEM; /* We'll try again later. */ } - /* Collapse two adjacent packets if worthwhile and we can. */ - if (!(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN) && - (skb->len < (cur_mss >> 1)) && - (!tcp_skb_is_last(sk, skb)) && - (tcp_write_queue_next(sk, skb) != tcp_send_head(sk)) && - (skb_shinfo(skb)->nr_frags == 0 && - skb_shinfo(tcp_write_queue_next(sk, skb))->nr_frags == 0) && - (tcp_skb_pcount(skb) == 1 && - tcp_skb_pcount(tcp_write_queue_next(sk, skb)) == 1) && - (sysctl_tcp_retrans_collapse != 0)) - tcp_retrans_try_collapse(sk, skb, cur_mss); + tcp_retrans_try_collapse(sk, skb, cur_mss); /* Some Solaris stacks overoptimize and ignore the FIN on a * retransmit when old data is attached. So strip it off -- cgit v1.2.3