kernel.git/net/sched/Kconfig, branch linux-5.0.y

tc: Add support for configuring the taprio scheduler

2018-10-04T20:52:23Z

This traffic scheduler allows traffic classes states (transmission allowed/not allowed, in the simplest case) to be scheduled, according to a pre-generated time sequence. This is the basis of the IEEE 802.1Qbv specification. Example configuration: tc qdisc replace dev enp3s0 parent root handle 100 taprio \ num_tc 3 \ map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 \ queues 1@0 1@1 2@2 \ base-time 1528743495910289987 \ sched-entry S 01 300000 \ sched-entry S 02 300000 \ sched-entry S 04 300000 \ clockid CLOCK_TAI The configuration format is similar to mqprio. The main difference is the presence of a schedule, built by multiple "sched-entry" definitions, each entry has the following format: sched-entry The only supported is "S", which means "SetGateStates", following the IEEE 802.1Qbv-2015 definition (Table 8-6). is a bitmask where each bit is a associated with a traffic class, so bit 0 (the least significant bit) being "on" means that traffic class 0 is "active" for that schedule entry. is a time duration in nanoseconds that specifies for how long that state defined by and should be held before moving to the next entry. This schedule is circular, that is, after the last entry is executed it starts from the first one, indefinitely. The other parameters can be defined as follows: - base-time: specifies the instant when the schedule starts, if 'base-time' is a time in the past, the schedule will start at base-time + (N * cycle-time) where N is the smallest integer so the resulting time is greater than "now", and "cycle-time" is the sum of all the intervals of the entries in the schedule; - clockid: specifies the reference clock to be used; The parameters should be similar to what the IEEE 802.1Q family of specification defines. Signed-off-by: Vinicius Costa Gomes Signed-off-by: David S. Miller

net/sched: add skbprio scheduler

2018-07-24T21:44:00Z

Skbprio (SKB Priority Queue) is a queueing discipline that prioritizes packets according to their skb->priority field. Under congestion, already-enqueued lower priority packets will be dropped to make space available for higher priority packets. Skbprio was conceived as a solution for denial-of-service defenses that need to route packets with different priorities as a means to overcome DoS attacks. v5 *Do not reference qdisc_dev(sch)->tx_queue_len for setting limit. Instead set default sch->limit to 64. v4 *Drop Documentation/networking/sch_skbprio.txt doc file to move it to tc man page for Skbprio, in iproute2. v3 *Drop max_limit parameter in struct skbprio_sched_data and instead use sch->limit. *Reference qdisc_dev(sch)->tx_queue_len only once, during initialisation for qdisc (previously being referenced every time qdisc changes). *Move qdisc's detailed description from in-code to Documentation/networking. *When qdisc is saturated, enqueue incoming packet first before dequeueing lowest priority packet in queue - improves usage of call stack registers. *Introduce and use overlimit stat to keep track of number of dropped packets. v2 *Use skb->priority field rather than DS field. Rename queueing discipline as SKB Priority Queue (previously Gatekeeper Priority Queue). *Queueing discipline is made classful to expose Skbprio's internal priority queues. Signed-off-by: Nishanth Devarajan Reviewed-by: Sachin Paryani Reviewed-by: Cody Doucette Reviewed-by: Michel Machado Acked-by: Cong Wang Signed-off-by: David S. Miller

sched: fix trailing whitespace

2018-07-24T21:10:42Z

Remove trailing whitespace and blank lines at EOF Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller

sched: Add Common Applications Kept Enhanced (cake) qdisc

2018-07-11T03:06:34Z

sch_cake targets the home router use case and is intended to squeeze the most bandwidth and latency out of even the slowest ISP links and routers, while presenting an API simple enough that even an ISP can configure it. Example of use on a cable ISP uplink: tc qdisc add dev eth0 cake bandwidth 20Mbit nat docsis ack-filter To shape a cable download link (ifb and tc-mirred setup elided) tc qdisc add dev ifb0 cake bandwidth 200mbit nat docsis ingress wash CAKE is filled with: * A hybrid Codel/Blue AQM algorithm, "Cobalt", tied to an FQ_Codel derived Flow Queuing system, which autoconfigures based on the bandwidth. * A novel "triple-isolate" mode (the default) which balances per-host and per-flow FQ even through NAT. * An deficit based shaper, that can also be used in an unlimited mode. * 8 way set associative hashing to reduce flow collisions to a minimum. * A reasonable interpretation of various diffserv latency/loss tradeoffs. * Support for zeroing diffserv markings for entering and exiting traffic. * Support for interacting well with Docsis 3.0 shaper framing. * Extensive support for DSL framing types. * Support for ack filtering. * Extensive statistics for measuring, loss, ecn markings, latency variation. A paper describing the design of CAKE is available at https://arxiv.org/abs/1804.07617, and will be published at the 2018 IEEE International Symposium on Local and Metropolitan Area Networks (LANMAN). This patch adds the base shaper and packet scheduler, while subsequent commits add the optional (configurable) features. The full userspace API and most data structures are included in this commit, but options not understood in the base version will be ignored. Various versions baking have been available as an out of tree build for kernel versions going back to 3.10, as the embedded router world has been running a few years behind mainline Linux. A stable version has been generally available on lede-17.01 and later. sch_cake replaces a combination of iptables, tc filter, htb and fq_codel in the sqm-scripts, with sane defaults and vastly simpler configuration. CAKE's principal author is Jonathan Morton, with contributions from Kevin Darbyshire-Bryant, Toke Høiland-Jørgensen, Sebastian Moeller, Ryan Mounce, Tony Ambardar, Dean Scarff, Nils Andreas Svee, Dave Täht, and Loganaden Velvindron. Testing from Pete Heist, Georgios Amanakis, and the many other members of the cake@lists.bufferbloat.net mailing list. tc -s qdisc show dev eth2 qdisc cake 8017: root refcnt 2 bandwidth 1Gbit diffserv3 triple-isolate split-gso rtt 100.0ms noatm overhead 38 mpu 84 Sent 51504294511 bytes 37724591 pkt (dropped 6, overlimits 64958695 requeues 12) backlog 0b 0p requeues 12 memory used: 1053008b of 15140Kb capacity estimate: 970Mbit min/max network layer size: 28 / 1500 min/max overhead-adjusted size: 84 / 1538 average network hdr offset: 14 Bulk Best Effort Voice thresh 62500Kbit 1Gbit 250Mbit target 5.0ms 5.0ms 5.0ms interval 100.0ms 100.0ms 100.0ms pk_delay 5us 5us 6us av_delay 3us 2us 2us sp_delay 2us 1us 1us backlog 0b 0b 0b pkts 3164050 25030267 9530280 bytes 3227519915 35396974782 12879808898 way_inds 0 8 0 way_miss 21 366 25 way_cols 0 0 0 drops 5 0 1 marks 0 0 0 ack_drop 0 0 0 sp_flows 1 3 0 bk_flows 0 1 1 un_flows 0 0 0 max_len 68130 68130 68130 Tested-by: Pete Heist Tested-by: Georgios Amanakis Signed-off-by: Dave Taht Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: David S. Miller

net/sched: Introduce the ETF Qdisc

2018-07-04T13:30:27Z

The ETF (Earliest TxTime First) qdisc uses the information added earlier in this series (the socket option SO_TXTIME and the new role of sk_buff->tstamp) to schedule packets transmission based on absolute time. For some workloads, just bandwidth enforcement is not enough, and precise control of the transmission of packets is necessary. Example: $ tc qdisc replace dev enp2s0 parent root handle 100 mqprio num_tc 3 \ map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 queues 1@0 1@1 2@2 hw 0 $ tc qdisc add dev enp2s0 parent 100:1 etf delta 100000 \ clockid CLOCK_TAI In this example, the Qdisc will provide SW best-effort for the control of the transmission time to the network adapter, the time stamp in the socket will be in reference to the clockid CLOCK_TAI and packets will leave the qdisc "delta" (100000) nanoseconds before its transmission time. The ETF qdisc will buffer packets sorted by their txtime. It will drop packets on enqueue() if their skbuff clockid does not match the clock reference of the Qdisc. Moreover, on dequeue(), a packet will be dropped if it expires while being enqueued. The qdisc also supports the SO_TXTIME deadline mode. For this mode, it will dequeue a packet as soon as possible and change the skb timestamp to 'now' during etf_dequeue(). Note that both the qdisc's and the SO_TXTIME ABIs allow for a clockid to be configured, but it's been decided that usage of CLOCK_TAI should be enforced until we decide to allow for other clockids to be used. The rationale here is that PTP times are usually in the TAI scale, thus no other clocks should be necessary. For now, the qdisc will return EINVAL if any clocks other than CLOCK_TAI are used. Signed-off-by: Jesus Sanchez-Palencia Signed-off-by: Vinicius Costa Gomes Signed-off-by: David S. Miller

net: sched: add em_ipt ematch for calling xtables matches

2018-02-21T18:15:33Z

The commit a new tc ematch for using netfilter xtable matches. This allows early classification as well as mirroning/redirecting traffic based on logic implemented in netfilter extensions. Current supported use case is classification based on the incoming IPSec state used during decpsulation using the 'policy' iptables extension (xt_policy). The module dynamically fetches the netfilter match module and calls it using a fake xt_action_param structure based on validated userspace provided parameters. As the xt_policy match does not access skb->data, no skb modifications are needed on match. Signed-off-by: Eyal Birger Signed-off-by: David S. Miller

net/sched: kconfig: Remove blank help texts

2018-01-31T15:26:30Z

Blank help texts are probably either a typo, a Kconfig misunderstanding, or some kind of half-committing to adding a help text (in which case a TODO comment would be clearer, if the help text really can't be added right away). Best to remove them, IMO. Signed-off-by: Ulf Magnusson Signed-off-by: David S. Miller

net/sched: Introduce Credit Based Shaper (CBS) qdisc

2017-10-27T16:48:02Z

This queueing discipline implements the shaper algorithm defined by the 802.1Q-2014 Section 8.6.8.2 and detailed in Annex L. It's primary usage is to apply some bandwidth reservation to user defined traffic classes, which are mapped to different queues via the mqprio qdisc. Only a simple software implementation is added for now. Signed-off-by: Vinicius Costa Gomes Signed-off-by: Jesus Sanchez-Palencia Tested-by: Henrik Austad Signed-off-by: Jeff Kirsher

net: sched: select cls when cls_act is enabled

2017-06-05T14:56:36Z

It really makes no sense to have cls_act enabled without cls. In that case, the cls_act code is dead. So select it. This also fixes an issue recently reported by kbuild robot: [linux-next:master 1326/4151] net/sched/act_api.c:37:18: error: implicit declaration of function 'tcf_chain_get' Reported-by: kbuild test robot Fixes: db50514f9a9c ("net: sched: add termination action to allow goto chain") Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller

Subject: net: allow configuring default qdisc

2017-04-17T17:23:06Z

Since 3.12 it has been possible to configure the default queuing discipline via sysctl. This patch adds ability to configure the default queue discipline in kernel configuration. This is useful for environments where configuring the value from userspace is difficult to manage. The default is still the same as before (pfifo_fast) and it is possible to change after kernel init with sysctl. This is similar to how TCP congestion control works. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller