fff-dhcp: increase dns cachesize

The default cachesize for dnsmasq is 150 entries, which results in a
poor cache hit rate.

Raise the default to 1024 to provide better cache hit rates on all
devices while still keeping memory usage in check.

Further increase the cachesize to 8192 entries for systems with enough
ram (currently more than 64MB).

The memory usage will increase roughly 100B per entry.

The size was chosen empirically. Higher values don't seem to increase
cache hit rate a lot.

Signed-off-by: Johannes Kimmel <fff@bareminimum.eu>
Reviewed-by: Fabian Bläse <fabian@blaese.de>
Johannes Kimmel 1 year ago committed by Fabian Bläse
parent 0e8c32a363
commit 87d923c1ef

@ -1,3 +1,10 @@
# Use a larger cachesize by default
# Increase cachesize for systems with enough memory
mem="$(awk '/^MemTotal:/ {print $2}' /proc/meminfo)"
[ "$mem" -gt 65536 ] && cachesize=8192
uci batch >/dev/null <<EOF
delete dhcp.@dnsmasq[0]
delete dhcp.lan
@ -12,6 +19,7 @@ uci batch >/dev/null <<EOF
set dhcp.@dnsmasq[-1].domain='fff.community'
set dhcp.@dnsmasq[-1].expandhosts='0'
set dhcp.@dnsmasq[-1].nonegcache='0'
set dhcp.@dnsmasq[-1].cachesize="$cachesize"
set dhcp.@dnsmasq[-1].authoritative='1'
set dhcp.@dnsmasq[-1].readethers='1'
set dhcp.@dnsmasq[-1].leasefile='/tmp/dhcp.leases'