Bug 193688

Summary:	kern.ipc.somaxconn isn't just for tcp
Product:	Documentation	Reporter:	Bram Van Steenlandt <bram>
Component:	Books & Articles	Assignee:	Mark Linimon <linimon>
Status:	Closed Feedback Timeout
Severity:	Affects Some People	CC:	bram, diego.casati
Priority:	Normal
Version:	Latest
Hardware:	Any
OS:	Any
URL:	https://www.freebsd.org/doc/handbook/configtuning-kernel-limits.html

Description Bram Van Steenlandt 2014-09-16 18:15:45 UTC

The handbook says:
12.11.1.2. kern.ipc.somaxconn

The kern.ipc.somaxconn sysctl(8) variable limits the size of the listen queue for accepting new TCP connections.

Isn't kern.ipc.somaxconn also for other sockets such as AF_UNIX ?

I've done some tests and this seems to be the case.

Comment 1 Diego Casati 2017-01-12 03:14:34 UTC

Rather an old ticket but I thought it was worth going over it. 

As of FreeBSD 10.0, somaxconn has been replaced by soacceptqueue as stated at the HISTORY section of listen(2):

HISTORY
     The listen() system call appeared in 4.2BSD.  The ability to configure
     the maximum backlog at run-time, and to use a negative backlog to request
     the maximum allowable value, was introduced in FreeBSD 2.2.  The
     kern.ipc.somaxconn sysctl(3) has been replaced with
     kern.ipc.soacceptqueue in FreeBSD 10.0 to prevent confusion about its
     actual functionality.  The original sysctl(3) kern.ipc.somaxconn is still
     available but hidden from a sysctl(3) -a output so that existing
     applications and scripts continue to work.

The handbook section has also been updated. 

thanks,
- dcasati

Comment 2 Mark Linimon freebsd_committer

2017-01-12 11:20:30 UTC

To submitter: do these later changes fix the problem?