qos-scripts update:

- rewrite the RED qdisc calculations and add some comments
this should fix the warnings about bursting (should also fix quirks with various linespeed settings)
- reduce the calculated overhead for upstream, while i'm at it...

SVN-Revision: 7782
owl
Felix Fietkau 2007-06-30 02:34:03 +00:00
parent 1449d4ce28
commit 8c0de17322
3 changed files with 32 additions and 11 deletions

View File

@ -9,7 +9,7 @@
include $(TOPDIR)/rules.mk
PKG_NAME:=qos-scripts
PKG_VERSION:=1.1.1
PKG_VERSION:=1.2.0
PKG_RELEASE:=1
PKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME)

View File

@ -261,7 +261,7 @@ start_interface() {
for dir in up${halfduplex} ${download:+down}; do
case "$dir" in
up)
[ "$overhead" = 1 ] && upload=$(($upload * 98 / 100 - (32 * 128 / $upload)))
[ "$overhead" = 1 ] && upload=$(($upload * 98 / 100 - (15 * 128 / $upload)))
dev="$device"
rate="$upload"
dl_mode=""

View File

@ -77,20 +77,41 @@ END {
# leaf qdisc
avpkt = 1200
for (i = 1; i <= n; i++) {
ql = int((avgrate[i] + linespeed) * 1024 / (8 * pktsize[i]))
printf "tc qdisc add dev "device" parent 1:"class[i]"0 handle "class[i]"00: "
# RED parameters - also used to determine the queue length for sfq
# calculate min value. for links <= 256 kbit, we use 1500 bytes
# use 50 ms queue length as min threshold for faster links
# max threshold is fixed to 3*min
base_pkt=3000
base_rate=256
min_lat=50
if (maxrate[i] <= base_rate) min = base_pkt
else min = int(maxrate[i] * 1024 / 8 * 0.05)
max = 3 * min
limit = (min + max) * 3
if (rtm1[i] > 0) {
# rt class - use sfq
print "sfq perturb 2 limit " ql
print "sfq perturb 2 limit " limit
} else {
# non-rt class - use red
min = int(maxrate[i] * 1024 / 8 * 0.05)
if (min < avpkt) min = avpkt
dqb = 8 * min;
max = int(2.1*min)
rburst = int((2*min + max) / (3 * avpkt))
# non-rt class - use RED
avpkt = pktsize[i]
# don't use avpkt values less than 500 bytes
if (avpkt < 500) avpkt = 500
# if avpkt is too close to min, scale down avpkt to allow proper bursting
if (avpkt > min * 0.70) avpkt *= 0.70
# according to http://www.cs.unc.edu/~jeffay/papers/IEEE-ToN-01.pdf a drop
# probability somewhere between 0.1 and 0.2 should be a good tradeoff
# between link utilization and response time (0.1: response; 0.2: utilization)
prob="0.12"
rburst=int((2*min + max) / (3 * avpkt))
if (rburst < 2) rburst = 2
print "red min " min " max " max " burst " rburst " avpkt " avpkt " limit " dqb " probability 0.04 ecn"
print "red min " min " max " max " burst " rburst " avpkt " avpkt " limit " limit " probability " prob " ecn"
}
}