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* reciprocal_divide: update/correction of the algorithmHannes Frederic Sowa2014-01-211-2/+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 Yingliang2014-01-191-19/+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-Hewapathirane2014-01-141-9/+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 Yingliang2013-12-101-1/+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 Pfeifer2013-10-251-1/+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 Dumazet2013-07-031-3/+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 Dumazet2013-07-011-24/+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 Dumazet2012-07-161-1/+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. Miller2012-05-071-4/+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. Miller2012-04-011-7/+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 Dumazet2012-02-191-4/+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
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| * 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 Pfeifer2011-12-121-4/+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 Pfeifer2011-11-301-0/+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 Dobriyan2011-06-211-0/+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. Miller2011-02-241-0/+1
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: update version and cleanupstephen hemminger2011-02-241-6/+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 hemminger2011-02-241-4/+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 hemminger2011-02-241-8/+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>
* netem: define NETEM_DIST_MAXstephen hemminger2011-02-241-1/+1
| | | | | | | | | Rather than magic constant in code, expose the maximum size of packet distribution table in API. In iproute2, q_netem defines MAX_DIST as 16K already. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: use vmalloc for distribution tablestephen hemminger2011-02-241-4/+18
| | | | | | | | The netem probability table can be large (up to 64K bytes) which may be too large to allocate in one contiguous chunk. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netem: cleanup dump codestephen hemminger2011-02-241-6/+3
| | | | | | | Use nla_put_nested to update netlink attribute value. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'master' of ↵David S. Miller2011-01-241-2/+1
|\ | | | | | | | | | | | | | | | | master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: net/sched/sch_hfsc.c net/sched/sch_htb.c net/sched/sch_tbf.c
| * net_sched: accurate bytes/packets stats/ratesEric Dumazet2011-01-201-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 44b8288308ac9d (net_sched: pfifo_head_drop problem), we fixed a problem with pfifo_head drops that incorrectly decreased sch->bstats.bytes and sch->bstats.packets Several qdiscs (CHOKe, SFQ, pfifo_head, ...) are able to drop a previously enqueued packet, and bstats cannot be changed, so bstats/rates are not accurate (over estimated) This patch changes the qdisc_bstats updates to be done at dequeue() time instead of enqueue() time. bstats counters no longer account for dropped frames, and rates are more correct, since enqueue() bursts dont have effect on dequeue() rate. 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>
* | net_sched: move TCQ_F_THROTTLED flagEric Dumazet2011-01-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 371121057607e (net: QDISC_STATE_RUNNING dont need atomic bit ops) I moved QDISC_STATE_RUNNING flag to __state container, located in the cache line containing qdisc lock and often dirtied fields. I now move TCQ_F_THROTTLED bit too, so that we let first cache line read mostly, and shared by all cpus. This should speedup HTB/CBQ for example. Not using test_bit()/__clear_bit()/__test_and_set_bit allows to use an "unsigned int" for __state container, reducing by 8 bytes Qdisc size. Introduce helpers to hide implementation details. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Patrick McHardy <kaber@trash.net> CC: Jesper Dangaard Brouer <hawk@diku.dk> CC: Jarek Poplawski <jarkao2@gmail.com> CC: Jamal Hadi Salim <hadi@cyberus.ca> CC: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net_sched: cleanupsEric Dumazet2011-01-191-3/+3
|/ | | | | | | | | Cleanup net/sched code to current CodingStyle and practices. Reduce inline abuse Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: factorize qdisc stats handlingEric Dumazet2011-01-101-4/+2
| | | | | | | | | | | | | | | | | HTB takes into account skb is segmented in stats updates. Generalize this to all schedulers. They should use qdisc_bstats_update() helper instead of manipulating bstats.bytes and bstats.packets Add bstats_update() helper too for classes that use gnet_stats_basic_packed fields. Note : Right now, TCQ_F_CAN_BYPASS shortcurt can be taken only if no stab is setup on qdisc. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: remove the unused parameter of qdisc_create_dflt()Changli Gao2010-10-211-2/+1
| | | | | | | | The first parameter dev isn't in use in qdisc_create_dflt(). Signed-off-by: Changli Gao <xiaosuo@gmail.com> Acked-by: Jamal Hadi Salim <hadi@cyberus.ca> Signed-off-by: David S. Miller <davem@davemloft.net>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* net: Move && and || to end of previous lineJoe Perches2009-11-291-6/+6
| | | | | | | | | | | Not including net/atm/ Compiled tested x86 allyesconfig only Added a > 80 column line or two, which I ignored. Existing checkpatch plaints willfully, cheerfully ignored. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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