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2013-03-29net: fq_codel: Fix off-by-one errorVijay Subramanian1-1/+1
Currently, we hold a max of sch->limit -1 number of packets instead of sch->limit packets. Fix this off-by-one error. Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-03fq_codel: dont reinit flow stateEric Dumazet1-1/+1
When fq_codel builds a new flow, it should not reset codel state. Codel algo needs to get previous values (lastcount, drop_next) to get proper behavior. Signed-off-by: Dave Taht <dave.taht@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Dave Taht <dave.taht@bufferbloat.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-16fq_codel: should use qdisc backlog as thresholdEric Dumazet1-2/+3
codel_should_drop() logic allows a packet being not dropped if queue size is under max packet size. In fq_codel, we have two possible backlogs : The qdisc global one, and the flow local one. The meaningful one for codel_should_drop() should be the global backlog, not the per flow one, so that thin flows can have a non zero drop/mark probability. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Dave Taht <dave.taht@bufferbloat.net> Cc: Kathleen Nichols <nichols@pollere.com> Cc: Van Jacobson <van@pollere.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-14net: codel: fix build errorsSasha Levin1-4/+5
Fix the following build error: net/sched/sch_fq_codel.c: In function 'fq_codel_dump_stats': net/sched/sch_fq_codel.c:464:3: error: unknown field 'qdisc_stats' specified in initializer net/sched/sch_fq_codel.c:464:3: warning: missing braces around initializer net/sched/sch_fq_codel.c:464:3: warning: (near initialization for 'st.<anonymous>') net/sched/sch_fq_codel.c:465:3: error: unknown field 'qdisc_stats' specified in initializer net/sched/sch_fq_codel.c:465:3: warning: excess elements in struct initializer net/sched/sch_fq_codel.c:465:3: warning: (near initialization for 'st') net/sched/sch_fq_codel.c:466:3: error: unknown field 'qdisc_stats' specified in initializer net/sched/sch_fq_codel.c:466:3: warning: excess elements in struct initializer net/sched/sch_fq_codel.c:466:3: warning: (near initialization for 'st') net/sched/sch_fq_codel.c:467:3: error: unknown field 'qdisc_stats' specified in initializer net/sched/sch_fq_codel.c:467:3: warning: excess elements in struct initializer net/sched/sch_fq_codel.c:467:3: warning: (near initialization for 'st') make[1]: *** [net/sched/sch_fq_codel.o] Error 1 Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-12fq_codel: Fair Queue Codel AQMEric Dumazet1-0/+624
Fair Queue Codel packet scheduler Principles : - Packets are classified (internal classifier or external) on flows. - This is a Stochastic model (as we use a hash, several flows might be hashed on same slot) - Each flow has a CoDel managed queue. - Flows are linked onto two (Round Robin) lists, so that new flows have priority on old ones. - For a given flow, packets are not reordered (CoDel uses a FIFO) - head drops only. - ECN capability is on by default. - Very low memory footprint (64 bytes per flow) tc qdisc ... fq_codel [ limit PACKETS ] [ flows number ] [ target TIME ] [ interval TIME ] [ noecn ] [ quantum BYTES ] defaults : 1024 flows, 10240 packets limit, quantum : device MTU target : 5ms (CoDel default) interval : 100ms (CoDel default) Impressive results on load : class htb 1:1 root leaf 10: prio 0 quantum 1514 rate 200000Kbit ceil 200000Kbit burst 1475b/8 mpu 0b overhead 0b cburst 1475b/8 mpu 0b overhead 0b level 0 Sent 43304920109 bytes 33063109 pkt (dropped 0, overlimits 0 requeues 0) rate 201691Kbit 28595pps backlog 0b 312p requeues 0 lended: 33063109 borrowed: 0 giants: 0 tokens: -912 ctokens: -912 class fq_codel 10:1735 parent 10: (dropped 1292, overlimits 0 requeues 0) backlog 15140b 10p requeues 0 deficit 1514 count 1 lastcount 1 ldelay 7.1ms class fq_codel 10:4524 parent 10: (dropped 1291, overlimits 0 requeues 0) backlog 16654b 11p requeues 0 deficit 1514 count 1 lastcount 1 ldelay 7.1ms class fq_codel 10:4e74 parent 10: (dropped 1290, overlimits 0 requeues 0) backlog 6056b 4p requeues 0 deficit 1514 count 1 lastcount 1 ldelay 6.4ms dropping drop_next 92.0ms class fq_codel 10:628a parent 10: (dropped 1289, overlimits 0 requeues 0) backlog 7570b 5p requeues 0 deficit 1514 count 1 lastcount 1 ldelay 5.4ms dropping drop_next 90.9ms class fq_codel 10:a4b3 parent 10: (dropped 302, overlimits 0 requeues 0) backlog 16654b 11p requeues 0 deficit 1514 count 1 lastcount 1 ldelay 7.1ms class fq_codel 10:c3c2 parent 10: (dropped 1284, overlimits 0 requeues 0) backlog 13626b 9p requeues 0 deficit 1514 count 1 lastcount 1 ldelay 5.9ms class fq_codel 10:d331 parent 10: (dropped 299, overlimits 0 requeues 0) backlog 15140b 10p requeues 0 deficit 1514 count 1 lastcount 1 ldelay 7.0ms class fq_codel 10:d526 parent 10: (dropped 12160, overlimits 0 requeues 0) backlog 35870b 211p requeues 0 deficit 1508 count 12160 lastcount 1 ldelay 15.3ms dropping drop_next 247us class fq_codel 10:e2c6 parent 10: (dropped 1288, overlimits 0 requeues 0) backlog 15140b 10p requeues 0 deficit 1514 count 1 lastcount 1 ldelay 7.1ms class fq_codel 10:eab5 parent 10: (dropped 1285, overlimits 0 requeues 0) backlog 16654b 11p requeues 0 deficit 1514 count 1 lastcount 1 ldelay 5.9ms class fq_codel 10:f220 parent 10: (dropped 1289, overlimits 0 requeues 0) backlog 15140b 10p requeues 0 deficit 1514 count 1 lastcount 1 ldelay 7.1ms qdisc htb 1: root refcnt 6 r2q 10 default 1 direct_packets_stat 0 ver 3.17 Sent 43331086547 bytes 33092812 pkt (dropped 0, overlimits 66063544 requeues 71) rate 201697Kbit 28602pps backlog 0b 260p requeues 71 qdisc fq_codel 10: parent 1:1 limit 10240p flows 65536 target 5.0ms interval 100.0ms ecn Sent 43331086547 bytes 33092812 pkt (dropped 949359, overlimits 0 requeues 0) rate 201697Kbit 28602pps backlog 189352b 260p requeues 0 maxpacket 1514 drop_overlimit 0 new_flow_count 5582 ecn_mark 125593 new_flows_len 0 old_flows_len 11 PING 172.30.42.18 (172.30.42.18) 56(84) bytes of data. 64 bytes from 172.30.42.18: icmp_req=1 ttl=64 time=0.227 ms 64 bytes from 172.30.42.18: icmp_req=2 ttl=64 time=0.165 ms 64 bytes from 172.30.42.18: icmp_req=3 ttl=64 time=0.166 ms 64 bytes from 172.30.42.18: icmp_req=4 ttl=64 time=0.151 ms 64 bytes from 172.30.42.18: icmp_req=5 ttl=64 time=0.164 ms 64 bytes from 172.30.42.18: icmp_req=6 ttl=64 time=0.172 ms 64 bytes from 172.30.42.18: icmp_req=7 ttl=64 time=0.175 ms 64 bytes from 172.30.42.18: icmp_req=8 ttl=64 time=0.183 ms 64 bytes from 172.30.42.18: icmp_req=9 ttl=64 time=0.158 ms 64 bytes from 172.30.42.18: icmp_req=10 ttl=64 time=0.200 ms 10 packets transmitted, 10 received, 0% packet loss, time 8999ms rtt min/avg/max/mdev = 0.151/0.176/0.227/0.022 ms Much better than SFQ because of priority given to new flows, and fast path dirtying less cache lines. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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