git: c3cc8223dd82 - stable/15 - tcp: bump max rcv buffer size for autoscaling

The branch stable/15 has been updated by tuexen:

URL: https://cgit.FreeBSD.org/src/commit/?id=c3cc8223dd825a1f81cef6be14f8bbba74dc3d2a

commit c3cc8223dd825a1f81cef6be14f8bbba74dc3d2a
Author:     Michael Tuexen <tuexen@FreeBSD.org>
AuthorDate: 2025-10-15 20:24:51 +0000
Commit:     Michael Tuexen <tuexen@FreeBSD.org>
CommitDate: 2025-10-19 07:34:46 +0000

    tcp: bump max rcv 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, Peter Lei, jtl, thj
    Sponsored by:           Netflix, Inc.
    Differential Revision:  https://reviews.freebsd.org/D52871
    
    (cherry picked from commit baeff75122e5cdb669c920414e054224270383d7)
---
 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 dd27ec77c1af..2146b0cac48f 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -219,7 +219,7 @@ SYSCTL_INT(_net_inet_tcp, OID_AUTO, recvbuf_auto, CTLFLAG_VNET | CTLFLAG_RW,
     &VNET_NAME(tcp_do_autorcvbuf), 0,
     "Enable automatic receive buffer sizing");
 
-VNET_DEFINE(int, tcp_autorcvbuf_max) = 2*1024*1024;
+VNET_DEFINE(int, tcp_autorcvbuf_max) = 8*1024*1024;
 SYSCTL_INT(_net_inet_tcp, OID_AUTO, recvbuf_max, CTLFLAG_VNET | CTLFLAG_RW,
     &VNET_NAME(tcp_autorcvbuf_max), 0,
     "Max size of automatic receive buffer");