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* net: sched: enable per cpu qstatsJohn Fastabend2014-09-301-2/+3
| | | | | | | | After previous patches to simplify qstats the qstats can be made per cpu with a packed union in Qdisc struct. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: sched: restrict use of qstats qlenJohn Fastabend2014-09-301-5/+4
| | | | | | | | | | | | | | | | | | | | This removes the use of qstats->qlen variable from the classifiers and makes it an explicit argument to gnet_stats_copy_queue(). The qlen represents the qdisc queue length and is packed into the qstats at the last moment before passnig to user space. By handling it explicitely we avoid, in the percpu stats case, having to figure out which per_cpu variable to put it in. It would probably be best to remove it from qstats completely but qstats is a user space ABI and can't be broken. A future patch could make an internal only qstats structure that would avoid having to allocate an additional u32 variable on the Qdisc struct. This would make the qstats struct 128bits instead of 128+32. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: sched: make bstats per cpu and estimator RCU safeJohn Fastabend2014-09-301-2/+2
| | | | | | | | | | | | | | | | | In order to run qdisc's without locking statistics and estimators need to be handled correctly. To resolve bstats make the statistics per cpu. And because this is only needed for qdiscs that are running without locks which is not the case for most qdiscs in the near future only create percpu stats when qdiscs set the TCQ_F_CPUSTATS flag. Next because estimators use the bstats to calculate packets per second and bytes per second the estimator code paths are updated to use the per cpu statistics. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: qdisc: use rcu prefix and silence sparse warningsJohn Fastabend2014-09-131-2/+4
| | | | | | | | | | | | | | | Add __rcu notation to qdisc handling by doing this we can make smatch output more legible. And anyways some of the cases should be using rcu_dereference() see qdisc_all_tx_empty(), qdisc_tx_chainging(), and so on. Also *wake_queue() API is commonly called from driver timer routines without rcu lock or rtnl lock. So I added rcu_read_lock() blocks around netif_wake_subqueue and netif_tx_wake_queue. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: give visibility to mq slave qdiscsEric Dumazet2013-12-091-4/+6
| | | | | | | | | | | | | | | Commit 6da7c8fcbcbd ("qdisc: allow setting default queuing discipline") added the ability to change default qdisc from pfifo_fast to say fq But as most modern ethernet devices are multiqueue, we cant really see all the statistics from "tc -s qdisc show", as the default root qdisc is mq. This patch adds the calls to qdisc_list_add() to mq and mqprio Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* qdisc: allow setting default queuing disciplinestephen hemminger2013-08-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | By default, the pfifo_fast queue discipline has been used by default for all devices. But we have better choices now. This patch allow setting the default queueing discipline with sysctl. This allows easy use of better queueing disciplines on all devices without having to use tc qdisc scripts. It is intended to allow an easy path for distributions to make fq_codel or sfq the default qdisc. This patch also makes pfifo_fast more of a first class qdisc, since it is now possible to manually override the default and explicitly use pfifo_fast. The behavior for systems who do not use the sysctl is unchanged, they still get pfifo_fast Also removes leftover random # in sysctl net core. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: avoid requeues if possibleEric Dumazet2012-12-121-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With BQL being deployed, we can more likely have following behavior : We dequeue a packet from qdisc in dequeue_skb(), then we realize target tx queue is in XOFF state in sch_direct_xmit(), and we have to hold the skb into gso_skb for later. This shows in stats (tc -s qdisc dev eth0) as requeues. Problem of these requeues is that high priority packets can not be dequeued as long as this (possibly low prio and big TSO packet) is not removed from gso_skb. At 1Gbps speed, a full size TSO packet is 500 us of extra latency. In some cases, we know that all packets dequeued from a qdisc are for a particular and known txq : - If device is non multi queue - For all MQ/MQPRIO slave qdiscs This patch introduces a new qdisc flag, TCQ_F_ONETXQUEUE to mark this capability, so that dequeue_skb() is allowed to dequeue a packet only if the associated txq is not stopped. This indeed reduce latencies for high prio packets (or improve fairness with sfq/fq_codel), and almost remove qdisc 'requeues'. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: Stop using NLA_PUT*().David S. Miller2012-04-011-1/+2
| | | | | | | 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>
* mqprio: Avoid panic if no options are providedThomas Graf2011-12-221-1/+1
| | | | | | | | | Userspace may not provide TCA_OPTIONS, in fact tc currently does so not do so if no arguments are specified on the command line. Return EINVAL instead of panicing. Signed-off-by: Thomas Graf <tgraf@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Fix files explicitly needing to include module.hPaul Gortmaker2011-10-311-0/+1
| | | | | | | | | With calls to modular infrastructure, these files really needs the full module.h header. Call it out so some of the cleanups of implicit and unrequired includes elsewhere can be cleaned up. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* mqprio: cleanupsstephen hemminger2011-02-231-2/+4
| | | | | | | | | * make qdisc_ops local * add sparse annotation about expected unlock/unlock in dump_class_stats * fix indentation Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* sch_mqprio: Always set num_tc to 0 in mqprio_destroy()Ben Hutchings2011-02-141-7/+7
| | | | | | | | | All the cleanup code in mqprio_destroy() is currently conditional on priv->qdiscs being non-null, but that condition should only apply to the per-queue qdisc cleanup. We should always set the number of traffic classes back to 0 here. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
* net_sched: sch_mqprio: dont leak kernel memoryEric Dumazet2011-01-261-1/+1
| | | | | | | | | mqprio_dump() should make sure all fields of struct tc_mqprio_qopt are initialized. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: TCQ_F_CAN_BYPASS generalizationEric Dumazet2011-01-211-1/+0
| | | | | | | | | | | | | | | | Now qdisc stab is handled before TCQ_F_CAN_BYPASS test in __dev_xmit_skb(), we can generalize TCQ_F_CAN_BYPASS to other qdiscs than pfifo_fast : pfifo, bfifo, pfifo_head_drop and sfq SFQ is special because it can have external classifiers, and in these cases, we cannot bypass queue discipline (packet could be dropped by classifier) without admin asking it, or further changes. Its worth doing this, especially for SFQ, avoiding dirtying memory in case no packets are already waiting in queue. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: implement a root container qdisc sch_mqprioJohn Fastabend2011-01-191-0/+417
This implements a mqprio queueing discipline that by default creates a pfifo_fast qdisc per tx queue and provides the needed configuration interface. Using the mqprio qdisc the number of tcs currently in use along with the range of queues alloted to each class can be configured. By default skbs are mapped to traffic classes using the skb priority. This mapping is configurable. Configurable parameters, struct tc_mqprio_qopt { __u8 num_tc; __u8 prio_tc_map[TC_BITMASK + 1]; __u8 hw; __u16 count[TC_MAX_QUEUE]; __u16 offset[TC_MAX_QUEUE]; }; Here the count/offset pairing give the queue alignment and the prio_tc_map gives the mapping from skb->priority to tc. The hw bit determines if the hardware should configure the count and offset values. If the hardware bit is set then the operation will fail if the hardware does not implement the ndo_setup_tc operation. This is to avoid undetermined states where the hardware may or may not control the queue mapping. Also minimal bounds checking is done on the count/offset to verify a queue does not exceed num_tx_queues and that queue ranges do not overlap. Otherwise it is left to user policy or hardware configuration to create useful mappings. It is expected that hardware QOS schemes can be implemented by creating appropriate mappings of queues in ndo_tc_setup(). One expected use case is drivers will use the ndo_setup_tc to map queue ranges onto 802.1Q traffic classes. This provides a generic mechanism to map network traffic onto these traffic classes and removes the need for lower layer drivers to know specifics about traffic types. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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