ingress police effect egress bandwidth

ingress police effect egress bandwidth

[fanfei]

Hi
My Os is Red Hat 6.2 server kernel 2.6.32
I set an ingress filter for a 1Gb ethernet interface, script:

DEV=eth1
IP=xx.xx.xx.xx
RATEPmbps
BURST=5m
MTU=1mb
tc qdisc del dev $DEV ingress
tc qdisc add dev $DEV handle ffff: ingress
tc filter add dev $DEV parent ffff: \
protocol ip prio 20 \
u32 match ip src $IP/32 \
police rate $RATE burst $BURST mtu $MTU \
drop flowid :1


I'm not getting a 50mbps band, it be 200kbps ~ 18mbps according <burst,
mtu> value I set.
After I run the script several times, I find the egress bandwith has
been limited to 30mbps.


qdisc on eth1:

tc -s qdisc show dev eth1
qdisc mq 0: root
Sent 13862277239 bytes 2746355 pkt (dropped 0, overlimits 0 requeues 0)
rate 0bit 0pps backlog 0b 0p requeues 0
qdisc ingress ffff: parent ffff:fff1 ----------------
Sent 1372858005 bytes 176228 pkt (dropped 1539, overlimits 0 requeues 0)
rate 0bit 0pps backlog 0b 0p requeues 0

ingress filter:

tc -s filter show dev eth1 parent ffff:
filter protocol ip pref 20 u32
filter protocol ip pref 20 u32 fh 800: ht divisor 1
filter protocol ip pref 20 u32 fh 800::800 order 2048 key ht 800 bkt 0
flowid :1 (rule hit 174518 success 173742)
match c0a8017c/ffffffff at 12 (success 173742 )
police 0x18 rate 400000Kbit burst 5Mb mtu 1Mb action drop overhead 0b
ref 1 bind 1

Sent 1372696737 bytes 173742 pkts (dropped 1539, overlimits 1539)

restart network, and run the script, the egress bandwith is correct
(about 100mbps).
After run script 2~3 times, the egress bandwith again limit to less than
30mbps (depends on RATE in ingress filter)
who can tell how to avoid this happened, and how to get the <burst,mtu>
value to get the rate I want (50mbps)