qos-scripts: replace sfq/red with fq_codel - massively improves latency under load
authorFelix Fietkau <nbd@openwrt.org>
Wed, 16 May 2012 15:23:16 +0000 (15:23 +0000)
committerFelix Fietkau <nbd@openwrt.org>
Wed, 16 May 2012 15:23:16 +0000 (15:23 +0000)
SVN-Revision: 31759

package/qos-scripts/files/usr/lib/qos/generate.sh
package/qos-scripts/files/usr/lib/qos/tcrules.awk

index 07b9559fdd3600645715eacdbd65f091d7430c96..bb1d7ed11116ce4f2a7a56a9777c6e40266d9f61 100755 (executable)
@@ -344,8 +344,7 @@ tc filter add dev $device parent ffff: protocol ip prio 1 u32 match u32 0 0 flow
        fi
        add_insmod cls_fw
        add_insmod sch_hfsc
-       add_insmod sch_sfq
-       add_insmod sch_red
+       add_insmod sch_fq_codel
 
        cat <<EOF
 ${INSMOD:+$INSMOD$N}${dev_up:+$dev_up
index 0021eaa7ce7272590a1f0e98a329cd763499531a..a19b651920c6bf266decad8b4b465c2f3a265962 100644 (file)
@@ -79,47 +79,9 @@ END {
        # leaf qdisc
        avpkt = 1200
        for (i = 1; i <= n; 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 (qdisc[i] != "") {
-                       # user specified qdisc
-                       print qdisc[i] " limit " limit
-               } else if (rtm1[i] > 0) {
-                       # rt class - use sfq
-                       print "sfq perturb 2 limit "  limit
-               } else {
-                       # 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 " limit " probability " prob " ecn"
-               }
+               print "tc qdisc add dev "device" parent 1:"class[i]"0 handle "class[i]"00: fq_codel"
        }
-       
+
        # filter rule
        for (i = 1; i <= n; i++) {
                print "tc filter add dev "device" parent 1: prio "class[i]" protocol ip handle "class[i]"/0xff fw flowid 1:"class[i] "0"