root@support00:~# uname -aKU FreeBSD support00.local 10.1-RELEASE-p10 FreeBSD 10.1-RELEASE-p10 #0: Wed May 13 06:54:13 UTC 2015 root@amd64-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC amd64 1001000 1001000 root@support00:~# sysctl -a | fgrep somaxconn root@support00:~# sysctl kern.ipc.somaxconn kern.ipc.somaxconn: 256 root@support00:~#
That behavior is requested explicitly with CTLFLAG_SKIP: SYSCTL_PROC(_kern_ipc, KIPC_SOMAXCONN, somaxconn, CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_SKIP, 0, sizeof(int), sysctl_somaxconn, "I", "Maximum listen socket pending connection accept queue size (compat)");
------------------------------------------------------------------------ r241781 | andre | 2012-10-20 05:53:14 -0700 (Sat, 20 Oct 2012) | 10 lines Hide the unfortunate named sysctl kern.ipc.somaxconn from sysctl -a output and replace it with a new visible sysctl kern.ipc.acceptqueue of the same functionality. It specifies the maximum length of the accept queue on a listen socket. The old kern.ipc.somaxconn remains available for reading and writing for compatibility reasons so that existing programs, scripts and configurations continue to work. There no plans to ever remove the orginal and now hidden kern.ipc.somaxconn. ------------------------------------------------------------------------
(In reply to Marcus Reid from comment #2) Oh, thanks for the explanation. I've tried to find info about this sysctl in src/UPDATING file.
Created attachment 160417 [details] make de description of the sysctl a bit more informative