#include <asm/div64.h>
#include <net/tcp.h>
-
-/* Vegas variables */
-struct vegas {
- u32 beg_snd_nxt; /* right edge during last RTT */
- u32 beg_snd_una; /* left edge during last RTT */
- u32 beg_snd_cwnd; /* saves the size of the cwnd */
- u8 doing_vegas_now;/* if true, do vegas for this RTT */
- u16 cntRTT; /* # of RTTs measured within last RTT */
- u32 minRTT; /* min of RTTs measured within last RTT (in usec) */
- u32 baseRTT; /* the min of all Vegas RTT measurements seen (in usec) */
-};
-
-/* There are several situations when we must "re-start" Vegas:
- *
- * o when a connection is established
- * o after an RTO
- * o after fast recovery
- * o when we send a packet and there is no outstanding
- * unacknowledged data (restarting an idle connection)
- *
- * In these circumstances we cannot do a Vegas calculation at the
- * end of the first RTT, because any calculation we do is using
- * stale info -- both the saved cwnd and congestion feedback are
- * stale.
- *
- * Instead we must wait until the completion of an RTT during
- * which we actually receive ACKs.
- */
-static inline void vegas_enable(struct sock *sk)
-{
- const struct tcp_sock *tp = tcp_sk(sk);
- struct vegas *vegas = inet_csk_ca(sk);
-
- /* Begin taking Vegas samples next time we send something. */
- vegas->doing_vegas_now = 1;
-
- /* Set the beginning of the next send window. */
- vegas->beg_snd_nxt = tp->snd_nxt;
-
- vegas->cntRTT = 0;
- vegas->minRTT = 0x7fffffff;
-}
-
-/* Stop taking Vegas samples for now. */
-static inline void vegas_disable(struct sock *sk)
-{
- struct vegas *vegas = inet_csk_ca(sk);
-
- vegas->doing_vegas_now = 0;
-}
-
-static void tcp_vegas_init(struct sock *sk)
-{
- struct vegas *vegas = inet_csk_ca(sk);
-
- vegas->baseRTT = 0x7fffffff;
- vegas_enable(sk);
-}
-
-static void tcp_vegas_state(struct sock *sk, u8 ca_state)
-{
-
- if (ca_state == TCP_CA_Open)
- vegas_enable(sk);
- else
- vegas_disable(sk);
-}
-
-/* Do RTT sampling needed for Vegas.
- * Basically we:
- * o min-filter RTT samples from within an RTT to get the current
- * propagation delay + queuing delay (we are min-filtering to try to
- * avoid the effects of delayed ACKs)
- * o min-filter RTT samples from a much longer window (forever for now)
- * to find the propagation delay (baseRTT)
- */
-static void tcp_vegas_pkts_acked(struct sock *sk, u32 cnt, ktime_t last)
-{
- struct vegas *vegas = inet_csk_ca(sk);
- u32 vrtt;
-
- /* Never allow zero rtt or baseRTT */
- vrtt = (ktime_to_ns(net_timedelta(last)) / NSEC_PER_USEC) + 1;
-
- /* Filter to find propagation delay: */
- if (vrtt < vegas->baseRTT)
- vegas->baseRTT = vrtt;
-
- /* Find the min RTT during the last RTT to find
- * the current prop. delay + queuing delay:
- */
- vegas->minRTT = min(vegas->minRTT, vrtt);
- vegas->cntRTT++;
-}
-
-/*
- * If the connection is idle and we are restarting,
- * then we don't want to do any Vegas calculations
- * until we get fresh RTT samples. So when we
- * restart, we reset our Vegas state to a clean
- * slate. After we get acks for this flight of
- * packets, _then_ we can make Vegas calculations
- * again.
- */
-static void tcp_vegas_cwnd_event(struct sock *sk, enum tcp_ca_event event)
-{
- if (event == CA_EVENT_CWND_RESTART ||
- event == CA_EVENT_TX_START)
- tcp_vegas_init(sk);
-}
-
-/* Extract info for Tcp socket info provided via netlink. */
-static void tcp_vegas_get_info(struct sock *sk, u32 ext,
- struct sk_buff *skb)
-{
- const struct vegas *ca = inet_csk_ca(sk);
- if (ext & (1 << (INET_DIAG_VEGASINFO - 1))) {
- struct tcpvegas_info *info;
-
- info = RTA_DATA(__RTA_PUT(skb, INET_DIAG_VEGASINFO,
- sizeof(*info)));
-
- info->tcpv_enabled = ca->doing_vegas_now;
- info->tcpv_rttcnt = ca->cntRTT;
- info->tcpv_rtt = ca->baseRTT;
- info->tcpv_minrtt = ca->minRTT;
- rtattr_failure: ;
- }
-}
-
-
projects / powerpc.git / blobdiff