summaryrefslogtreecommitdiffstats
path: root/net/sched/sch_netem.c (follow)
Commit message (Collapse)AuthorAgeFilesLines
* net_sched: update hierarchical backlog tooWANG Cong2016-02-291-1/+2
| | | | | | | | | | | | When the bottom qdisc decides to, for example, drop some packet, it calls qdisc_tree_decrease_qlen() to update the queue length for all its ancestors, we need to update the backlog too to keep the stats on root qdisc accurate. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: introduce qdisc_replace() helperWANG Cong2016-02-291-9/+1
| | | | | | | | | Remove nearly duplicated code and prepare for the following patch. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: sched: deprecate enqueue_root()Eric Dumazet2015-05-111-2/+2
| | | | | | | | | Only left enqueue_root() user is netem, and it looks not necessary : qdisc_skb_cb(skb)->pkt_len is preserved after one skb_clone() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: Fixes byte backlog accounting for the first of two chained netem ↵Beshay, Joseph2015-04-081-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | instances Fixes byte backlog accounting for the first of two chained netem instances. Bytes backlog reported now corresponds to the number of queued packets. When two netem instances are chained, for instance to apply rate and queue limitation followed by packet delay, the number of backlogged bytes reported by the first netem instance is wrong. It reports the sum of bytes in the queues of the first and second netem. The first netem reports the correct number of backlogged packets but not bytes. This is shown in the example below. Consider a chain of two netem schedulers created using the following commands: $ tc -s qdisc replace dev veth2 root handle 1:0 netem rate 10000kbit limit 100 $ tc -s qdisc add dev veth2 parent 1:0 handle 2: netem delay 50ms Start an iperf session to send packets out on the specified interface and monitor the backlog using tc: $ tc -s qdisc show dev veth2 Output using unpatched netem: qdisc netem 1: root refcnt 2 limit 100 rate 10000Kbit Sent 98422639 bytes 65434 pkt (dropped 123, overlimits 0 requeues 0) backlog 172694b 73p requeues 0 qdisc netem 2: parent 1: limit 1000 delay 50.0ms Sent 98422639 bytes 65434 pkt (dropped 0, overlimits 0 requeues 0) backlog 63588b 42p requeues 0 The interface used to produce this output has an MTU of 1500. The output for backlogged bytes behind netem 1 is 172694b. This value is not correct. Consider the total number of sent bytes and packets. By dividing the number of sent bytes by the number of sent packets, we get an average packet size of ~=1504. If we divide the number of backlogged bytes by packets, we get ~=2365. This is due to the first netem incorrectly counting the 63588b which are in netem 2's queue as being in its own queue. To verify this is the case, we subtract them from the reported value and divide by the number of packets as follows: 172694 - 63588 = 109106 bytes actualled backlogged in netem 1 109106 / 73 packets ~= 1494 bytes (which matches our MTU) The root cause is that the byte accounting is not done at the same time with packet accounting. The solution is to update the backlog value every time the packet queue is updated. Signed-off-by: Joseph D Beshay <joseph.beshay@utdallas.edu> Acked-by: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: add rbnode to struct sk_buffEric Dumazet2014-11-031-20/+7
| | | | | | | | | | | Yaogong replaces TCP out of order receive queue by an RB tree. As netem already does a private skb->{next/prev/tstamp} union with a 'struct rb_node', lets do this in a cleaner way. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yaogong Wang <wygivan@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: sched: implement qstat helper routinesJohn Fastabend2014-09-301-8/+7
| | | | | | | | | This adds helpers to manipulate qstats logic and replaces locations that touch the counters directly. This simplifies future patches to push qstats onto per cpu counters. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: use the new API kvfree()WANG Cong2014-06-051-6/+1
| | | | | | | | | It is available since v3.15-rc5. Cc: Pablo Neira Ayuso <pablo@netfilter.org> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* sch_netem: replace magic numbers with enumerate in get_loss_clgYang Yingliang2014-02-171-2/+2
| | | | | | | Replace two magic numbers which intialize clgstate::state. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* sch_netem: replace magic numbers with enumerate in GE modelYang Yingliang2014-02-141-4/+9
| | | | | | | | Replace some magic numbers which describe states of GE model loss generator with enumerate. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* sch_netem: change some func's param from "struct Qdisc *" to "struct ↵Yang Yingliang2014-02-141-15/+10
| | | | | | | | | | | netem_sched_data *" In netem_change(), we have already get "struct netem_sched_data *q". Replace params of get_correlation() and other similar functions with "struct netem_sched_data *q". Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* sch_netem: return errcode before setting paramsYang Yingliang2014-02-141-10/+29
| | | | | | | | | | get_dist_table() and get_loss_clg() may be failed. These two functions should be called after setting the members of qdisc_priv(sch), or it will break the old settings while either of them is failed. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* reciprocal_divide: update/correction of the algorithmHannes Frederic Sowa2014-01-221-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jakub Zawadzki noticed that some divisions by reciprocal_divide() were not correct [1][2], which he could also show with BPF code after divisions are transformed into reciprocal_value() for runtime invariance which can be passed to reciprocal_divide() later on; reverse in BPF dump ended up with a different, off-by-one K in some situations. This has been fixed by Eric Dumazet in commit aee636c4809fa5 ("bpf: do not use reciprocal divide"). This follow-up patch improves reciprocal_value() and reciprocal_divide() to work in all cases by using Granlund and Montgomery method, so that also future use is safe and without any non-obvious side-effects. Known problems with the old implementation were that division by 1 always returned 0 and some off-by-ones when the dividend and divisor where very large. This seemed to not be problematic with its current users, as far as we can tell. Eric Dumazet checked for the slab usage, we cannot surely say so in the case of flex_array. Still, in order to fix that, we propose an extension from the original implementation from commit 6a2d7a955d8d resp. [3][4], by using the algorithm proposed in "Division by Invariant Integers Using Multiplication" [5], Torbjörn Granlund and Peter L. Montgomery, that is, pseudocode for q = n/d where q, n, d is in u32 universe: 1) Initialization: int l = ceil(log_2 d) uword m' = floor((1<<32)*((1<<l)-d)/d)+1 int sh_1 = min(l,1) int sh_2 = max(l-1,0) 2) For q = n/d, all uword: uword t = (n*m')>>32 q = (t+((n-t)>>sh_1))>>sh_2 The assembler implementation from Agner Fog [6] also helped a lot while implementing. We have tested the implementation on x86_64, ppc64, i686, s390x; on x86_64/haswell we're still half the latency compared to normal divide. Joint work with Daniel Borkmann. [1] http://www.wireshark.org/~darkjames/reciprocal-buggy.c [2] http://www.wireshark.org/~darkjames/set-and-dump-filter-k-bug.c [3] https://gmplib.org/~tege/division-paper.pdf [4] http://homepage.cs.uiowa.edu/~jones/bcd/divide.html [5] http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1.2556 [6] http://www.agner.org/optimize/asmlib.zip Reported-by: Jakub Zawadzki <darkjames-ws@darkjames.pl> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Austin S Hemmelgarn <ahferroin7@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: Jesse Gross <jesse@nicira.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Andy Gospodarek <andy@greyhouse.net> Cc: Veaceslav Falico <vfalico@redhat.com> Cc: Jay Vosburgh <fubar@us.ibm.com> Cc: Jakub Zawadzki <darkjames-ws@darkjames.pl> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* sch_netem: replace magic numbers with enumerateYang Yingliang2014-01-201-19/+28
| | | | | | | | Replace some magic numbers which describe states of 4-state model loss generator with enumerate. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: replace macros net_random and net_srandom with direct calls to prandomAruna-Hewapathirane2014-01-151-9/+10
| | | | | | | | | | | | This patch removes the net_random and net_srandom macros and replaces them with direct calls to the prandom ones. As new commits only seem to use prandom_u32 there is no use to keep them around. This change makes it easier to grep for users of prandom_u32. Signed-off-by: Aruna-Hewapathirane <aruna.hewapathirane@gmail.com> Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* sch_netem: support of 64bit ratesYang Yingliang2013-12-311-2/+13
| | | | | | | | | Add a new attribute to support 64bit rates so that tc can use them to break the 32bit limit. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* sch_netem: more precise length of packetsYang Yingliang2013-12-311-1/+1
| | | | | | | | | | | With TSO/GSO/GRO packets, skb->len doesn't represent a precise amount of bytes on wire. This patch replace skb->len with qdisc_pkt_len(skb) which is more precise. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: add space around '>' and before '('Yang Yingliang2013-12-111-1/+1
| | | | | | | | Spaces required around that '>' (ctx:VxV) and before the open parenthesis '('. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: fix gemodel loss generatorstephen hemminger2013-11-301-1/+1
| | | | | | | | | | | | Patch from developers of the alternative loss models, downloaded from: http://netgroup.uniroma2.it/twiki/bin/view.cgi/Main/NetemCLG "in case 2, of the switch we change the direction of the inequality to net_random()>clg->a3, because clg->a3 is h in the GE model and when h is 0 all packets will be lost." Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: fix loss 4 state modelstephen hemminger2013-11-301-2/+2
| | | | | | | | | | | Patch from developers of the alternative loss models, downloaded from: http://netgroup.uniroma2.it/twiki/bin/view.cgi/Main/NetemCLG "In the case 1 of the switch statement in the if conditions we need to add clg->a4 to clg->a1, according to the model." Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: missing break in ge loss generatorstephen hemminger2013-11-301-0/+1
| | | | | | | | | There is a missing break statement in the Gilbert Elliot loss model generator which makes state machine behave incorrectly. Reported-by: Martin Burri <martin.burri@ch.abb.com Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: markov loss model transition fixHagen Paul Pfeifer2013-10-261-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The transition from markov state "3 => lost packets within a burst period" to "1 => successfully transmitted packets within a gap period" has no *additional* loss event. The loss already happen for transition from 1 -> 3, this additional loss will make things go wild. E.g. transition probabilities: p13: 10% p31: 100% Expected: Ploss = p13 / (p13 + p31) Ploss = ~9.09% ... but it isn't. Even worse: we get a double loss - each time. So simple don't return true to indicate loss, rather break and return false. Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net> Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Stefano Salsano <stefano.salsano@uniroma2.it> Cc: Fabio Ludovici <fabio.ludovici@yahoo.it> Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: free skb's in tree on resetstephen hemminger2013-10-111-0/+16
| | | | | | | | | Netem can leak memory because packets get stored in red-black tree and it is not cleared on reset. Reported by: Сергеев Сергей <adron@yapic.net> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: update backlog after dropstephen hemminger2013-10-111-0/+1
| | | | | | | | | | When packet is dropped from rb-tree netem the backlog statistic should also be updated. Reported-by: Сергеев Сергей <adron@yapic.net> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: Introduce skb_orphan_partial() helperEric Dumazet2013-07-311-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 547669d483e578 ("tcp: xps: fix reordering issues") added unexpected reorders in case netem is used in a MQ setup for high performance test bed. ETH=eth0 tc qd del dev $ETH root 2>/dev/null tc qd add dev $ETH root handle 1: mq for i in `seq 1 32` do tc qd add dev $ETH parent 1:$i netem delay 100ms done As all tcp packets are orphaned by netem, TCP stack believes it can set skb->ooo_okay on all packets. In order to allow producers to send more packets, we want to keep sk_wmem_alloc from reaching sk_sndbuf limit. We can do that by accounting one byte per skb in netem queues, so that TCP stack is not fooled too much. Tested: With above MQ/netem setup, scaling number of concurrent flows gives linear results and no reorders/retransmits lpq83:~# for n in 1 10 20 30 40 50 60 70 80 90 100 do echo -n "n:$n " ; ./super_netperf $n -H 10.7.7.84; done n:1 198.46 n:10 2002.69 n:20 4000.98 n:30 6006.35 n:40 8020.93 n:50 10032.3 n:60 12081.9 n:70 13971.3 n:80 16009.7 n:90 17117.3 n:100 17425.5 Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: fix possible NULL deref in netem_dequeue()Eric Dumazet2013-07-041-3/+5
| | | | | | | | | | | | | commit aec0a40a6f7884 ("netem: use rb tree to implement the time queue") added a regression if a child qdisc is attached to netem, as we perform a NULL dereference. Fix this by adding a temporary variable to cache netem_skb_cb(skb)->time_to_send. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: use rb tree to implement the time queueEric Dumazet2013-07-021-24/+85
| | | | | | | | | | | | | | | | | | | | | | | | | | Following typical setup to implement a ~100 ms RTT and big amount of reorders has very poor performance because netem implements the time queue using a linked list. ----------------------------------------------------------- ETH=eth0 IFB=ifb0 modprobe ifb ip link set dev $IFB up tc qdisc add dev $ETH ingress 2>/dev/null tc filter add dev $ETH parent ffff: \ protocol ip u32 match u32 0 0 flowid 1:1 action mirred egress \ redirect dev $IFB ethtool -K $ETH gro off tso off gso off tc qdisc add dev $IFB root netem delay 50ms 10ms limit 100000 tc qd add dev $ETH root netem delay 50ms limit 100000 --------------------------------------------------------- Switch netem time queue to a rb tree, so this kind of setup can work at high speed. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: fix delay calculation in rate extensionJohannes Naab2013-01-291-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The delay calculation with the rate extension introduces in v3.3 does not properly work, if other packets are still queued for transmission. For the delay calculation to work, both delay types (latency and delay introduces by rate limitation) have to be handled differently. The latency delay for a packet can overlap with the delay of other packets. The delay introduced by the rate however is separate, and can only start, once all other rate-introduced delays finished. Latency delay is from same distribution for each packet, rate delay depends on the packet size. .: latency delay -: rate delay x: additional delay we have to wait since another packet is currently transmitted .....---- Packet 1 .....xx------ Packet 2 .....------ Packet 3 ^^^^^ latency stacks ^^ rate delay doesn't stack ^^ latency stacks -----> time When a packet is enqueued, we first consider the latency delay. If other packets are already queued, we can reduce the latency delay until the last packet in the queue is send, however the latency delay cannot be <0, since this would mean that the rate is overcommitted. The new reference point is the time at which the last packet will be send. To find the time, when the packet should be send, the rate introduces delay has to be added on top of that. Signed-off-by: Johannes Naab <jn@stusta.de> Acked-by: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: refine early skb orphaningEric Dumazet2012-07-171-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | netem does an early orphaning of skbs. Doing so breaks TCP Small Queue or any mechanism relying on socket sk_wmem_alloc feedback. Ideally, we should perform this orphaning after the rate module and before the delay module, to mimic what happens on a real link : skb orphaning is indeed normally done at TX completion, before the transit on the link. +-------+ +--------+ +---------------+ +-----------------+ + Qdisc +---> Device +--> TX completion +--> links / hops +-> + + + xmit + + skb orphaning + + propagation + +-------+ +--------+ +---------------+ +-----------------+ < rate limiting > < delay, drops, reorders > If netem is used without delay feature (drops, reorders, rate limiting), then we should avoid early skb orphaning, to keep pressure on sockets as long as packets are still in qdisc queue. Ideally, netem should be refactored to implement delay module as the last stage. Current algorithm merges the two phases (rate limiting + delay) so its not correct. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Cc: Mark Gordon <msg@google.com> Cc: Andreas Terzis <aterzis@google.com> Cc: Yuchung Cheng <ycheng@google.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: add limitation to reordered packetsEric Dumazet2012-07-091-27/+15
| | | | | | | | | | | | | | | | | | | Fix two netem bugs : 1) When a frame was dropped by tfifo_enqueue(), drop counter was incremented twice. 2) When reordering is triggered, we enqueue a packet without checking queue limit. This can OOM pretty fast when this is repeated enough, since skbs are orphaned, no socket limit can help in this situation. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Mark Gordon <msg@google.com> Cc: Andreas Terzis <aterzis@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2012-05-081-4/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: drivers/net/ethernet/intel/e1000e/param.c drivers/net/wireless/iwlwifi/iwl-agn-rx.c drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c drivers/net/wireless/iwlwifi/iwl-trans.h Resolved the iwlwifi conflict with mainline using 3-way diff posted by John Linville and Stephen Rothwell. In 'net' we added a bug fix to make iwlwifi report a more accurate skb->truesize but this conflicted with RX path changes that happened meanwhile in net-next. In e1000e a conflict arose in the validation code for settings of adapter->itr. 'net-next' had more sophisticated logic so that logic was used. Signed-off-by: David S. Miller <davem@davemloft.net>
| * netem: fix possible skb leakEric Dumazet2012-05-011-4/+2
| | | | | | | | | | | | | | | | | | | | skb_checksum_help(skb) can return an error, we must free skb in this case. qdisc_drop(skb, sch) can also be feeded with a NULL skb (if skb_unshare() failed), so lets use this generic helper. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | netem: add ECN capabilityEric Dumazet2012-05-011-3/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add ECN (Explicit Congestion Notification) marking capability to netem tc qdisc add dev eth0 root netem drop 0.5 ecn Instead of dropping packets, try to ECN mark them. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Cc: Stephen Hemminger <shemminger@vyatta.com> Acked-by: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* | pkt_sched: Stop using NLA_PUT*().David S. Miller2012-04-021-7/+14
|/ | | | | | | These macros contain a hidden goto, and are thus extremely error prone and make code hard to audit. Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: fix dequeueEric Dumazet2012-02-201-4/+2
| | | | | | | | | | | | | | commit 50612537e9 (netem: fix classful handling) added two errors in netem_dequeue() 1) After checking skb at the head of tfifo queue for time constraints, it dequeues tail skb, thus adding unwanted reordering. 2) qdisc stats are updated twice per packet (one when packet dequeued from tfifo, once when delivered) Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Make qdisc_skb_cb upper size bound explicit.David S. Miller2012-02-091-2/+1
| | | | | | | | | | | Just like skb->cb[], so that qdisc_skb_cb can be encapsulated inside of other data structures. This is intended to be used by IPoIB so that it can remember addressing information stored at hard_header_ops->create() time that it can fetch when the packet gets to the transmit routine. Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: Fix off-by-one bug in reorderingVijay Subramanian2012-01-221-1/+1
| | | | | | | | | With netem reordering, a gap of N is supposed to reorder every Nth packet with given reorder probability. However, the code currently skips N packets and reorders every (N+1)th packet. Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: Bug in netem reorderingHagen Paul Pfeifer2012-01-051-2/+2
| | | | | | | | | | | | | | | Not now, but it looks you are correct. q->qdisc is NULL until another additional qdisc is attached (beside tfifo). See 50612537e9ab2969312. The following patch should work. From: Hagen Paul Pfeifer <hagen@jauu.net> netem: catch NULL pointer by updating the real qdisc statistic Reported-by: Vijay Subramanian <subramanian.vijay@gmail.com> Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: fix classful handlingEric Dumazet2011-12-301-121/+81
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 10f6dfcfde (Revert "sch_netem: Remove classful functionality") reintroduced classful functionality to netem, but broke basic netem behavior : netem uses an t(ime)fifo queue, and store timestamps in skb->cb[] If qdisc is changed, time constraints are not respected and other qdisc can destroy skb->cb[] and block netem at dequeue time. Fix this by always using internal tfifo, and optionally attach a child qdisc to netem (or a tree of qdiscs) Example of use : DEV=eth3 tc qdisc del dev $DEV root tc qdisc add dev $DEV root handle 30: est 1sec 8sec netem delay 20ms 10ms tc qdisc add dev $DEV handle 40:0 parent 30:0 tbf \ burst 20480 limit 20480 mtu 1514 rate 32000bps qdisc netem 30: root refcnt 18 limit 1000 delay 20.0ms 10.0ms Sent 190792 bytes 413 pkt (dropped 0, overlimits 0 requeues 0) rate 18416bit 3pps backlog 0b 0p requeues 0 qdisc tbf 40: parent 30: rate 256000bit burst 20Kb/8 mpu 0b lat 0us Sent 190792 bytes 413 pkt (dropped 6, overlimits 10 requeues 0) backlog 0b 5p requeues 0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2011-12-301-3/+4
|\
| * netem: dont call vfree() under spinlock and BH disabledEric Dumazet2011-12-241-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 6373a9a286 (netem: use vmalloc for distribution table) added a regression, since vfree() is called while holding a spinlock and BH being disabled. Fix this by doing the pointers swap in critical section, and freeing after spinlock release. Also add __GFP_NOWARN to the kmalloc() try, since we fallback to vmalloc(). Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | netem: loss model API sizesstephen hemminger2011-12-231-3/+3
| | | | | | | | | | | | | | | | | | | | The new netem loss model is configured with nested netlink messages. This code is being overly strict about sizes, and is easily confused by padding (or possible future expansion). Also message for gemodel is incorrect. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | netem: add cell concept to simulate special MAC behaviorHagen Paul Pfeifer2011-12-131-4/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This extension can be used to simulate special link layer characteristics. Simulate because packet data is not modified, only the calculation base is changed to delay a packet based on the original packet size and artificial cell information. packet_overhead can be used to simulate a link layer header compression scheme (e.g. set packet_overhead to -20) or with a positive packet_overhead value an additional MAC header can be simulated. It is also possible to "replace" the 14 byte Ethernet header with something else. cell_size and cell_overhead can be used to simulate link layer schemes, based on cells, like some TDMA schemes. Another application area are MAC schemes using a link layer fragmentation with a (small) header each. Cell size is the maximum amount of data bytes within one cell. Cell overhead is an additional variable to change the per-cell-overhead (e.g. 5 byte header per fragment). Example (5 kbit/s, 20 byte per packet overhead, cell-size 100 byte, per cell overhead 5 byte): tc qdisc add dev eth0 root netem rate 5kbit 20 100 5 Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | netem: fix build error on 32bit archesEric Dumazet2011-12-011-1/+4
| | | | | | | | | | | | | | | | ERROR: "__udivdi3" [net/sched/sch_netem.ko] undefined! Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* | netem: rate extensionHagen Paul Pfeifer2011-12-011-0/+40
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently netem is not in the ability to emulate channel bandwidth. Only static delay (and optional random jitter) can be configured. To emulate the channel rate the token bucket filter (sch_tbf) can be used. But TBF has some major emulation flaws. The buffer (token bucket depth/rate) cannot be 0. Also the idea behind TBF is that the credit (token in buckets) fills if no packet is transmitted. So that there is always a "positive" credit for new packets. In real life this behavior contradicts the law of nature where nothing can travel faster as speed of light. E.g.: on an emulated 1000 byte/s link a small IPv4/TCP SYN packet with ~50 byte require ~0.05 seconds - not 0 seconds. Netem is an excellent place to implement a rate limiting feature: static delay is already implemented, tfifo already has time information and the user can skip TBF configuration completely. This patch implement rate feature which can be configured via tc. e.g: tc qdisc add dev eth0 root netem rate 10kbit To emulate a link of 5000byte/s and add an additional static delay of 10ms: tc qdisc add dev eth0 root netem delay 10ms rate 5KBps Note: similar to TBF the rate extension is bounded to the kernel timing system. Depending on the architecture timer granularity, higher rates (e.g. 10mbit/s and higher) tend to transmission bursts. Also note: further queues living in network adaptors; see ethtool(8). Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@drr.davemloft.net>
* net: remove mm.h inclusion from netdevice.hAlexey Dobriyan2011-06-221-0/+1
| | | | | | | | | | | | | | | | | Remove linux/mm.h inclusion from netdevice.h -- it's unused (I've checked manually). To prevent mm.h inclusion via other channels also extract "enum dma_data_direction" definition into separate header. This tiny piece is what gluing netdevice.h with mm.h via "netdevice.h => dmaengine.h => dma-mapping.h => scatterlist.h => mm.h". Removal of mm.h from scatterlist.h was tried and was found not feasible on most archs, so the link was cutoff earlier. Hope people are OK with tiny include file. Note, that mm_types.h is still dragged in, but it is a separate story. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Fix common misspellingsLucas De Marchi2011-03-311-3/+3
| | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* sch_netem: Need to include vmalloc.hDavid S. Miller2011-02-251-0/+1
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: update version and cleanupstephen hemminger2011-02-251-6/+4
| | | | | | | | Get rid of debug message that are not useful, and enable the log messages in case of error. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: revised correlated loss generatorstephen hemminger2011-02-251-4/+270
| | | | | | | | | | | This is a patch originated with Stefano Salsano and Fabio Ludovici. It provides several alternative loss models for use with netem. This patch adds two state machine based loss models. See: http://netgroup.uniroma2.it/twiki/bin/view.cgi/Main/NetemCLG Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Revert "sch_netem: Remove classful functionality"stephen hemminger2011-02-251-8/+79
| | | | | | | | | | | | | | Many users have wanted the old functionality that was lost to be able to use pfifo as inner qdisc for netem. The reason that netem could not be classful with the older API was because of the limitations of the old dequeue/requeue interface; now that qdisc API has a peek function, there is no longer a problem with using any inner qdisc's. This reverts commit 02201464119334690fe209849843881b8e9cfa9f. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-15 11:15:31 +0100