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| author |   Eric Dumazet <edumazet@google.com> | 2019-12-23 12:27:50 -0800 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-12-27 16:29:14 -0800 |
| commit | 473900a504e510cf9175876de8892ad1e3e7efab (patch) | |
| tree | 7e7d854cf26dddd7dc142e08d90f08b27f9d88d9 /net/ipv4/tcp_cubic.c | |
| parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next (diff) | |
| download | linux-dev-473900a504e510cf9175876de8892ad1e3e7efab.tar.xz linux-dev-473900a504e510cf9175876de8892ad1e3e7efab.zip | |
tcp_cubic: optimize hystart_update()
We do not care which bit in ca->found is set.
We avoid accessing hystart and hystart_detect unless really needed,
possibly avoiding one cache line miss.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
| -rw-r--r-- | net/ipv4/tcp_cubic.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c index 1b3d032a4df2..297936033c33 100644 --- a/net/ipv4/tcp_cubic.c +++ b/net/ipv4/tcp_cubic.c @@ -381,9 +381,6 @@ static void hystart_update(struct sock *sk, u32 delay) struct tcp_sock *tp = tcp_sk(sk); struct bictcp *ca = inet_csk_ca(sk); - if (ca->found & hystart_detect) - return; - if (hystart_detect & HYSTART_ACK_TRAIN) { u32 now = bictcp_clock(); @@ -391,7 +388,7 @@ static void hystart_update(struct sock *sk, u32 delay) if ((s32)(now - ca->last_ack) <= hystart_ack_delta) { ca->last_ack = now; if ((s32)(now - ca->round_start) > ca->delay_min >> 4) { - ca->found |= HYSTART_ACK_TRAIN; + ca->found = 1; NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPHYSTARTTRAINDETECT); NET_ADD_STATS(sock_net(sk), @@ -412,7 +409,7 @@ static void hystart_update(struct sock *sk, u32 delay) } else { if (ca->curr_rtt > ca->delay_min + HYSTART_DELAY_THRESH(ca->delay_min >> 3)) { - ca->found |= HYSTART_DELAY; + ca->found = 1; NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPHYSTARTDELAYDETECT); NET_ADD_STATS(sock_net(sk), @@ -450,7 +447,7 @@ static void bictcp_acked(struct sock *sk, const struct ack_sample *sample) ca->delay_min = delay; /* hystart triggers when cwnd is larger than some threshold */ - if (hystart && tcp_in_slow_start(tp) && + if (!ca->found && hystart && tcp_in_slow_start(tp) && tp->snd_cwnd >= hystart_low_window) hystart_update(sk, delay); } |