git: 35707083c6fb - stable/14 - tcp: shift PRR sending cadence slightly left

The branch stable/14 has been updated by rscheff:

URL: https://cgit.FreeBSD.org/src/commit/?id=35707083c6fb47d28aea5e421ea99b3f0daea0a6

commit 35707083c6fb47d28aea5e421ea99b3f0daea0a6
Author:     Richard Scheffenegger <rscheff@FreeBSD.org>
AuthorDate: 2023-12-07 14:13:05 +0000
Commit:     Richard Scheffenegger <rscheff@FreeBSD.org>
CommitDate: 2023-12-14 10:13:09 +0000

    tcp: shift PRR sending cadence slightly left
    
    Don't let PRR pass up on the opportunity of clocking
    out packets on arrival of ACKs - by pulling sends
    forward by about half a packet. Prevents unexpectedly
    long runs of incoming ACKs without eliciting a
    packet transmission.
    
    MFC after:             1 week
    Reviewed By:           #transport, tuexen
    Sponsored by:          NetApp, Inc.
    Differential Revision: https://reviews.freebsd.org/D42918
    
    (cherry picked from commit 9276ad23b872eddc42e05304acb10bf5421b043c)
---
 sys/netinet/tcp_input.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 11ec7d2d74d2..15b7311f4605 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -3972,7 +3972,7 @@ tcp_do_prr_ack(struct tcpcb *tp, struct tcphdr *th, struct tcpopt *to)
 			    imax(1, tp->snd_nxt - tp->snd_una);
 		snd_cnt = howmany((long)tp->sackhint.prr_delivered *
 			    tp->snd_ssthresh, tp->sackhint.recover_fs) -
-			    tp->sackhint.prr_out;
+			    tp->sackhint.prr_out + maxseg - 1;
 	} else {
 		if (V_tcp_do_prr_conservative || (del_data == 0))
 			limit = tp->sackhint.prr_delivered -