| Message ID | 20171014114714.3694-4-natale.patriciello@gmail.com |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | TCP Wave | expand |
On Sat, 2017-10-14 at 13:47 +0200, Natale Patriciello wrote: > Usually, the pacing time is provided per-segment. In some occasion, this > time refers to the time between a group of segments. With this commit, add > the possibility for the congestion control module to tell the TCP socket > how many segments can be sent out before pausing and setting a pacing > timer. > > Signed-off-by: Natale Patriciello <natale.patriciello@gmail.com> > --- > include/net/tcp.h | 2 ++ > net/ipv4/tcp_output.c | 13 +++++++++---- > 2 files changed, 11 insertions(+), 4 deletions(-) > > diff --git a/include/net/tcp.h b/include/net/tcp.h > index e817f0669d0e..3561eca5a61f 100644 > --- a/include/net/tcp.h > +++ b/include/net/tcp.h > @@ -1019,6 +1019,8 @@ struct tcp_congestion_ops { > u64 (*get_pacing_time)(struct sock *sk); > /* the pacing timer is expired (optional) */ > void (*pacing_timer_expired)(struct sock *sk); > + /* get the # segs to send out when the timer expires (optional) */ > + u32 (*get_segs_per_round)(struct sock *sk); > > char name[TCP_CA_NAME_MAX]; > struct module *owner; > diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c > index 25b4cf0802f2..e37941e4328b 100644 > --- a/net/ipv4/tcp_output.c > +++ b/net/ipv4/tcp_output.c > @@ -2249,6 +2249,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, > int result; > bool is_cwnd_limited = false, is_rwnd_limited = false; > u32 max_segs; > + u32 pacing_allowed_segs = 0; > > sent_pkts = 0; > > @@ -2265,14 +2266,18 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, > max_segs = tcp_tso_segs(sk, mss_now); > tcp_mstamp_refresh(tp); > > - if (!tcp_pacing_timer_check(sk) && > - ca_ops && ca_ops->pacing_timer_expired) > - ca_ops->pacing_timer_expired(sk); > + if (!tcp_pacing_timer_check(sk)) { > + pacing_allowed_segs = 1; > + if (ca_ops && ca_ops->pacing_timer_expired) > + ca_ops->pacing_timer_expired(sk); > + if (ca_ops && ca_ops->get_segs_per_round) > + pacing_allowed_segs = ca_ops->get_segs_per_round(sk); > + } > > while ((skb = tcp_send_head(sk))) { > unsigned int limit; > > - if (tcp_pacing_check(sk)) > + if (sent_pkts >= pacing_allowed_segs) > break; > So, if pacing_allowed_segs == 0, we break immediately of the loop ???? Are you sure you have tested this patch with normal CC like CUBIC and BBR ?
diff --git a/include/net/tcp.h b/include/net/tcp.h index e817f0669d0e..3561eca5a61f 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1019,6 +1019,8 @@ struct tcp_congestion_ops { u64 (*get_pacing_time)(struct sock *sk); /* the pacing timer is expired (optional) */ void (*pacing_timer_expired)(struct sock *sk); + /* get the # segs to send out when the timer expires (optional) */ + u32 (*get_segs_per_round)(struct sock *sk); char name[TCP_CA_NAME_MAX]; struct module *owner; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 25b4cf0802f2..e37941e4328b 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2249,6 +2249,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, int result; bool is_cwnd_limited = false, is_rwnd_limited = false; u32 max_segs; + u32 pacing_allowed_segs = 0; sent_pkts = 0; @@ -2265,14 +2266,18 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, max_segs = tcp_tso_segs(sk, mss_now); tcp_mstamp_refresh(tp); - if (!tcp_pacing_timer_check(sk) && - ca_ops && ca_ops->pacing_timer_expired) - ca_ops->pacing_timer_expired(sk); + if (!tcp_pacing_timer_check(sk)) { + pacing_allowed_segs = 1; + if (ca_ops && ca_ops->pacing_timer_expired) + ca_ops->pacing_timer_expired(sk); + if (ca_ops && ca_ops->get_segs_per_round) + pacing_allowed_segs = ca_ops->get_segs_per_round(sk); + } while ((skb = tcp_send_head(sk))) { unsigned int limit; - if (tcp_pacing_check(sk)) + if (sent_pkts >= pacing_allowed_segs) break; tso_segs = tcp_init_tso_segs(skb, mss_now);
Usually, the pacing time is provided per-segment. In some occasion, this time refers to the time between a group of segments. With this commit, add the possibility for the congestion control module to tell the TCP socket how many segments can be sent out before pausing and setting a pacing timer. Signed-off-by: Natale Patriciello <natale.patriciello@gmail.com> --- include/net/tcp.h | 2 ++ net/ipv4/tcp_output.c | 13 +++++++++---- 2 files changed, 11 insertions(+), 4 deletions(-)