#!/bin/sh

# Copyright (c) 2018-2022, diyIT.org
# All rights reserved.
#
# BSD 2-Clause License ("Simplified BSD License" or "FreeBSD License")
# https://diyit.org/license/
#
#

MCLBYTES=2048
MSIZE=256
PHYSMEM=`sysctl -n hw.physmem`
PAGE_SIZE=`sysctl -n hw.pagesize`
VM_KMEM_SIZE=`sysctl -n vm.kmem_size`
REALMEM=${VM_KMEM_SIZE}
MAXMBUFMEM=`expr $REALMEM / 4 \* 3`
MJUMPAGESIZE=$PAGE_SIZE
MJUM9BYTES=`expr 9 \* 1024`
MJUM16BYTES=`expr 16 \* 1024`

#NMBCLUSTERS=`expr $MAXMBUFMEM / $MCLBYTES / 4` # higher # of jails
NMBCLUSTERS=`expr $MAXMBUFMEM / $MCLBYTES / 3`
NMBJUMBOP=`expr $MAXMBUFMEM / $MJUMPAGESIZE / 4`
NMBJUMBO9=`expr $MAXMBUFMEM / $MJUM9BYTES / 6`
NMBJUMBO16=`expr $MAXMBUFMEM / $MJUM16BYTES / 6`

NMBUFS=`sysctl -n kern.ipc.nmbufs`
NMMAX1=`expr $NMBCLUSTERS + $NMBJUMBOP + $NMBJUMBO9 + $NMBJUMBO16`
NMMAX2=`expr $MAXMBUFMEM / $MSIZE / 5`
if [ $NMMAX1 -gt $NMMAX2 ]; then
	NMBUFS=$NMMAX1
else
	NMBUFS=$NMMAX2
fi

show()
{
	echo "# `basename $0 ` suggested settings:"
	echo "kern.ipc.maxmbufmem=$MAXMBUFMEM"
	echo "kern.ipc.nmbclusters=$NMBCLUSTERS"
	echo "kern.ipc.nmbjumbop=$NMBJUMBOP"
	echo "kern.ipc.nmbjumbo9=$NMBJUMBO9"
	echo "kern.ipc.nmbjumbo16=$NMBJUMBO16"
	echo "kern.ipc.nmbufs=$NMBUFS"
}

compare()
{
	echo "kern.ipc.maxmbufmem:  `sysctl -n kern.ipc.maxmbufmem` (current)"
	echo "                 -->  $MAXMBUFMEM (suggested)"
	echo "kern.ipc.nmbclusters: `sysctl -n kern.ipc.nmbclusters`"
	echo "                  --> $NMBCLUSTERS"
	echo "kern.ipc.nmbjumbop:   `sysctl -n kern.ipc.nmbjumbop`"
	echo "                -->   $NMBJUMBOP"
	echo "kern.ipc.nmbjumbo9:   `sysctl -n kern.ipc.nmbjumbo9`"
	echo "                -->   $NMBJUMBO9"
	echo "kern.ipc.nmbjumbo16:  `sysctl -n kern.ipc.nmbjumbo16`"
	echo "                 -->  $NMBJUMBO16"
	echo "kern.ipc.nmbufs:      `sysctl -n kern.ipc.nmbufs`"
	echo "             -->      $NMBUFS"
    vmstat -z|grep -E '^ITEM|mbuf'
    netstat -m
    # vmstat -m
}

if [ $# -gt 0 ]; then
	if [ $1 == '-c' ]; then
		compare
		exit 0
	fi
fi

show