Status: Rejected in upstream (kern/77353)

postgresql documentation encourages to grow SysV IPC limits on *BSD systems
(which obviously applies to GNU/k*BSD ones too):

<quote>
    The options SYSVSHM and SYSVSEM need to be enabled when the kernel is compiled. (They are by default.) The maximum size of shared memory is determined by the option SHMMAXPGS (in pages). The following shows an example of how to set the various parameters:

options         SYSVSHM
options         SHMMAXPGS=4096
options         SHMSEG=256

options         SYSVSEM
options         SEMMNI=256
options         SEMMNS=512
options         SEMMNU=256
options         SEMMAP=256

    (On NetBSD and OpenBSD the key word is actually option singular.)

    You might also want to configure your kernel to lock shared memory into RAM and prevent it from being paged out to swap. Use the sysctl setting kern.ipc.shm_use_phys. 
</quote>

--- a/sys/amd64/conf/GENERIC
+++ b/sys/amd64/conf/GENERIC
@@ -55,6 +55,11 @@
 options 	SYSVSHM			# SYSV-style shared memory
 options 	SYSVMSG			# SYSV-style message queues
 options 	SYSVSEM			# SYSV-style semaphores
+options                SHMMAXPGS=4096
+options                SHMSEG=256
+options                SEMMNI=256
+options                SEMMNS=512
+options                SEMMNU=256
 options 	_KPOSIX_PRIORITY_SCHEDULING # POSIX P1003_1B real-time extensions
 options 	PRINTF_BUFR_SIZE=128	# Prevent printf output being interspersed.
 options 	KBD_INSTALL_CDEV	# install a CDEV entry in /dev
--- a/sys/i386/conf/GENERIC
+++ b/sys/i386/conf/GENERIC
@@ -56,6 +56,11 @@
 options 	SYSVSHM			# SYSV-style shared memory
 options 	SYSVMSG			# SYSV-style message queues
 options 	SYSVSEM			# SYSV-style semaphores
+options                SHMMAXPGS=4096
+options                SHMSEG=256
+options                SEMMNI=256
+options                SEMMNS=512
+options                SEMMNU=256
 options 	_KPOSIX_PRIORITY_SCHEDULING # POSIX P1003_1B real-time extensions
 options 	PRINTF_BUFR_SIZE=128	# Prevent printf output being interspersed.
 options 	KBD_INSTALL_CDEV	# install a CDEV entry in /dev