Re: [PATCH net-next 2/2] tcp_bbr: remove bbr->tso_segs_goal

2018-02-28 Thread Neal Cardwell
On Wed, Feb 28, 2018 at 5:40 PM, Eric Dumazet  wrote:
> Its value is computed then immediately used,
> there is no need to store it.
>
> Signed-off-by: Eric Dumazet 
> ---

Acked-by: Neal Cardwell 

This one also looks great to me. Thanks, Eric!

neal


[PATCH net-next 2/2] tcp_bbr: remove bbr->tso_segs_goal

2018-02-28 Thread Eric Dumazet
Its value is computed then immediately used,
there is no need to store it.

Signed-off-by: Eric Dumazet 
---
 net/ipv4/tcp_bbr.c | 12 
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c
index 
afc0567b8a98fbb718ba04505053aa3f62ab5784..c92014cb1e165df05651eb05f2133c2e9473d54f
 100644
--- a/net/ipv4/tcp_bbr.c
+++ b/net/ipv4/tcp_bbr.c
@@ -97,10 +97,9 @@ struct bbr {
packet_conservation:1,  /* use packet conservation? */
restore_cwnd:1,  /* decided to revert cwnd to old value */
round_start:1,   /* start of packet-timed tx->ack round? */
-   tso_segs_goal:7, /* segments we want in each skb we send */
idle_restart:1,  /* restarting after idle? */
probe_rtt_round_done:1,  /* a BBR_PROBE_RTT round at 4 pkts? */
-   unused:5,
+   unused:12,
lt_is_sampling:1,/* taking long-term ("LT") samples now? */
lt_rtt_cnt:7,/* round trips in long-term interval */
lt_use_bw:1; /* use lt_bw as our bw estimate? */
@@ -267,10 +266,9 @@ static u32 bbr_min_tso_segs(struct sock *sk)
return sk->sk_pacing_rate < (bbr_min_tso_rate >> 3) ? 1 : 2;
 }
 
-static void bbr_set_tso_segs_goal(struct sock *sk)
+static u32 bbr_tso_segs_goal(struct sock *sk)
 {
struct tcp_sock *tp = tcp_sk(sk);
-   struct bbr *bbr = inet_csk_ca(sk);
u32 segs, bytes;
 
/* Sort of tcp_tso_autosize() but ignoring
@@ -280,7 +278,7 @@ static void bbr_set_tso_segs_goal(struct sock *sk)
  GSO_MAX_SIZE - 1 - MAX_TCP_HEADER);
segs = max_t(u32, bytes / tp->mss_cache, bbr_min_tso_segs(sk));
 
-   bbr->tso_segs_goal = min(segs, 0x7FU);
+   return min(segs, 0x7FU);
 }
 
 /* Save "last known good" cwnd so we can restore it after losses or PROBE_RTT 
*/
@@ -351,7 +349,7 @@ static u32 bbr_target_cwnd(struct sock *sk, u32 bw, int 
gain)
cwnd = (((w * gain) >> BBR_SCALE) + BW_UNIT - 1) / BW_UNIT;
 
/* Allow enough full-sized skbs in flight to utilize end systems. */
-   cwnd += 3 * bbr->tso_segs_goal;
+   cwnd += 3 * bbr_tso_segs_goal(sk);
 
/* Reduce delayed ACKs by rounding up cwnd to the next even number. */
cwnd = (cwnd + 1) & ~1U;
@@ -827,7 +825,6 @@ static void bbr_main(struct sock *sk, const struct 
rate_sample *rs)
 
bw = bbr_bw(sk);
bbr_set_pacing_rate(sk, bw, bbr->pacing_gain);
-   bbr_set_tso_segs_goal(sk);
bbr_set_cwnd(sk, rs, rs->acked_sacked, bw, bbr->cwnd_gain);
 }
 
@@ -837,7 +834,6 @@ static void bbr_init(struct sock *sk)
struct bbr *bbr = inet_csk_ca(sk);
 
bbr->prior_cwnd = 0;
-   bbr->tso_segs_goal = 0;  /* default segs per skb until first ACK */
bbr->rtt_cnt = 0;
bbr->next_rtt_delivered = 0;
bbr->prev_ca_state = TCP_CA_Open;
-- 
2.16.2.395.g2e18187dfd-goog