git: 7d29554b36eb - stable/15 - tcp: bump max snd buffer size for autoscaling

The branch stable/15 has been updated by tuexen:

URL: https://cgit.FreeBSD.org/src/commit/?id=7d29554b36ebdedf24e4605e5681b95abed5acd6

commit 7d29554b36ebdedf24e4605e5681b95abed5acd6
Author:     Michael Tuexen <tuexen@FreeBSD.org>
AuthorDate: 2025-10-15 20:19:14 +0000
Commit:     Michael Tuexen <tuexen@FreeBSD.org>
CommitDate: 2025-10-19 07:33:58 +0000

    tcp: bump max snd buffer size for autoscaling
    
    This allows in higher throughput values with default settings.
    In the review I was proposing using 16 MB, but in the transport
    call today we settled on a more conservative value of 8.
    Bumping it further will be done in combination with mitigations
    for mbuf exhaustion attacks.
    
    Reviewed by:            rscheff, cc, glebius, Nick Banks, Peter Lei, jtl, thj, rrs
    Sponsored by:           Netflix, Inc.
    Differential Revision:  https://reviews.freebsd.org/D52872
    
    (cherry picked from commit 9dd4742ee51ae80639b087a60ce7d15811c2b1e6)
---
 sys/netinet/tcp_output.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
index 2dfb7faf56e3..208f72c4661c 100644
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -123,7 +123,7 @@ SYSCTL_INT(_net_inet_tcp, OID_AUTO, sendbuf_inc, CTLFLAG_VNET | CTLFLAG_RW,
 	&VNET_NAME(tcp_autosndbuf_inc), 0,
 	"Incrementor step size of automatic send buffer");
 
-VNET_DEFINE(int, tcp_autosndbuf_max) = 2*1024*1024;
+VNET_DEFINE(int, tcp_autosndbuf_max) = 8*1024*1024;
 SYSCTL_INT(_net_inet_tcp, OID_AUTO, sendbuf_max, CTLFLAG_VNET | CTLFLAG_RW,
 	&VNET_NAME(tcp_autosndbuf_max), 0,
 	"Max size of automatic send buffer");