Try to automatically calculate a better burst size for ingress policing

src/tc-gen

@@ -129,11 +129,14 @@ INGRESS TRAFFIC POLICING
 
  with a burst_time_seconds value of 0.005s, or 5ms.
 
- If BURST_SIZE is not set a default burst size of
+ The minimum recommended burst size is
 
  MTU * 10 = burst_size_in_bytes
 
- is used.
+ tc-gen tries to automatically calculate this for you, but in several
+ cases it is hard to determine the actual physical line rate for the
+ interface, so you may need to set BURST_SIZE manually for optimal
+ results.
 
  Ingress policing is very unreliable unless generic receive offload is
  disabled for the interface. For bonds and VLAN interfaces you have to
@@ -206,6 +209,15 @@ get_ecn () {
  fi
 }
 
+get_speed () {
+ # Takes interface as parameter
+ if [[ -r /sys/class/net/${1}/speed ]]; then
+ cat /sys/class/net/${1}/speed
+ else
+ echo 0
+ fi
+}
+
 get_mtu () {
  # Takes interface as parameter
  cat /sys/class/net/${1}/mtu
@@ -408,9 +420,16 @@ apply_ingress_policing () {
  ${TC} qdisc add dev ${IF_NAME} handle ffff: ingress
 
  local MTU=$(get_mtu ${IF_NAME})
+ local PHY_SPEED_MBITS=$(get_speed ${IF_NAME})
+ local BURST_TIME_MS=5
 
  if [[ -z ${BURST_SIZE} ]]; then
- BURST_SIZE=$(( ${MTU} * 10 ))
+ BURST_SIZE_MIN=$(( ${MTU} * 10 ))
+ BURST_SIZE=$(( ${PHY_SPEED_MBITS} * 1000 * ${BURST_TIME_MS} / 8 ))
+
+ if [[ ${BURST_SIZE} -lt ${BURST_SIZE_MIN} ]]; then
+ BURST_SIZE=${BURST_SIZE_MIN}
+ fi
  fi
 
  # Police all ingress traffic. Use prio 99 to make it possible to insert