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path: root/include/net/sch_generic.h
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2016-09-19sched: add and use qdisc_skb_head helpersFlorian Westphal
This change replaces sk_buff_head struct in Qdiscs with new qdisc_skb_head. Its similar to the skb_buff_head api, but does not use skb->prev pointers. Qdiscs will commonly enqueue at the tail of a list and dequeue at head. While skb_buff_head works fine for this, enqueue/dequeue needs to also adjust the prev pointer of next element. The ->prev pointer is not required for qdiscs so we can just leave it undefined and avoid one cacheline write access for en/dequeue. Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-19sched: remove qdisc arg from __qdisc_dequeue_headFlorian Westphal
Moves qdisc stat accouting to qdisc_dequeue_head. The only direct caller of the __qdisc_dequeue_head version open-codes this now. This allows us to later use __qdisc_dequeue_head as a replacement of __skb_dequeue() (which operates on sk_buff_head list). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-25net: minor optimization in qdisc_qstats_cpu_drop()Eric Dumazet
per_cpu_inc() is faster (at least on x86) than per_cpu_ptr(xxx)++; Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-10net: sched: convert qdisc linked list to hashtableJiri Kosina
Convert the per-device linked list into a hashtable. The primary motivation for this change is that currently, we're not tracking all the qdiscs in hierarchy (e.g. excluding default qdiscs), as the lookup performed over the linked list by qdisc_match_from_root() is rather expensive. The ultimate goal is to get rid of hidden qdiscs completely, which will bring much more determinism in user experience. Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-25net_sched: generalize bulk dequeueEric Dumazet
When qdisc bulk dequeue was added in linux-3.18 (commit 5772e9a3463b "qdisc: bulk dequeue support for qdiscs with TCQ_F_ONETXQUEUE"), it was constrained to some specific qdiscs. With some extra care, we can extend this to all qdiscs, so that typical traffic shaping solutions can benefit from small batches (8 packets in this patch). For example, HTB is often used on some multi queue device. And bonding/team are multi queue devices... Idea is to bulk-dequeue packets mapping to the same transmit queue. This brings between 35 and 80 % performance increase in HTB setup under pressure on a bonding setup : 1) NUMA node contention : 610,000 pps -> 1,110,000 pps 2) No node contention : 1,380,000 pps -> 1,930,000 pps Now we should work to add batches on the enqueue() side ;) Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: John Fastabend <john.r.fastabend@intel.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Florian Westphal <fw@strlen.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-25net_sched: drop packets after root qdisc lock is releasedEric Dumazet
Qdisc performance suffers when packets are dropped at enqueue() time because drops (kfree_skb()) are done while qdisc lock is held, delaying a dequeue() draining the queue. Nominal throughput can be reduced by 50 % when this happens, at a time we would like the dequeue() to proceed as fast as possible. Even FQ is vulnerable to this problem, while one of FQ goals was to provide some flow isolation. This patch adds a 'struct sk_buff **to_free' parameter to all qdisc->enqueue(), and in qdisc_drop() helper. I measured a performance increase of up to 12 %, but this patch is a prereq so that future batches in enqueue() can fly. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-15net_sched: add the ability to defer skb freeingEric Dumazet
qdisc are changed under RTNL protection and often while blocking BH and root qdisc spinlock. When lots of skbs need to be dropped, we free them under these locks causing TX/RX freezes, and more generally latency spikes. This commit adds rtnl_kfree_skbs(), used to queue skbs for deferred freeing. Actual freeing happens right after RTNL is released, with appropriate scheduling points. rtnl_qdisc_drop() can also be used in place of disc_drop() when RTNL is held. qdisc_reset_queue() and __qdisc_reset_queue() get the new behavior, so standard qdiscs like pfifo, pfifo_fast... have their ->reset() method automatically handled. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10net_sched: remove generic throttled managementEric Dumazet
__QDISC_STATE_THROTTLED bit manipulation is rather expensive for HTB and few others. I already removed it for sch_fq in commit f2600cf02b5b ("net: sched: avoid costly atomic operation in fq_dequeue()") and so far nobody complained. When one ore more packets are stuck in one or more throttled HTB class, a htb dequeue() performs two atomic operations to clear/set __QDISC_STATE_THROTTLED bit, while root qdisc lock is held. Removing this pair of atomic operations bring me a 8 % performance increase on 200 TCP_RR tests, in presence of throttled classes. This patch has no side effect, since nothing actually uses disc_is_throttled() anymore. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: net/sched/act_police.c net/sched/sch_drr.c net/sched/sch_hfsc.c net/sched/sch_prio.c net/sched/sch_red.c net/sched/sch_tbf.c In net-next the drop methods of the packet schedulers got removed, so the bug fixes to them in 'net' are irrelevant. A packet action unload crash fix conflicts with the addition of the new firstuse timestamp. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-09net: sched: fix qdisc->running lockdep annotationsEric Dumazet
1) qdisc_run_begin() is really using the equivalent of a trylock. Instead of using write_seqcount_begin(), use a combination of raw_write_seqcount_begin() and correct lockdep annotation. 2) sch_direct_xmit() should use regular spin_lock(root_lock) Fixes: f9eb8aea2a1e ("net_sched: transform qdisc running bit into a seqcount") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-08sched: place state, next_sched and gso_skb in same cacheline againFlorian Westphal
Earlier commits removed two members from struct Qdisc which places next_sched/gso_skb into a different cacheline than ->state. This restores the struct layout to what it was before the removal. Move the two members, then add an annotation so they all reside in the same cacheline. This adds a 16 byte hole after cpu_qstats. The hole could be closed but as it doesn't decrease total struct size just do it this way. Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-08sched: remove qdisc->dropFlorian Westphal
after removal of TCA_CBQ_OVL_STRATEGY from cbq scheduler, there are no more callers of ->drop() outside of other ->drop functions, i.e. nothing calls them. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-08sched: remove qdisc_rehape_failFlorian Westphal
After the removal of TCA_CBQ_POLICE in cbq scheduler qdisc->reshape_fail is always NULL, i.e. qdisc_rehape_fail is now the same as qdisc_drop. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-08cbq: remove TCA_CBQ_POLICE supportFlorian Westphal
iproute2 doesn't implement any cbq option that results in this attribute being sent to kernel. To make use of it, user would have to - patch iproute2 - add a class - attach a qdisc to the class (default pfifo doesn't work as q->handle is 0 and cbq_set_police() is a no-op in this case) - re-'add' the same class (tc class change ...) again - user must also specifiy a defmap (e.g. 'split 1:0 defmap 3f'), since this 'police' feature relies on its presence - the added qdisc must be one of bfifo, pfifo or netem If all of these conditions are met and _some_ leaf qdiscs, namely p/bfifo, netem, plug or tbf would drop a packet, kernel calls back into cbq, which will attempt to re-queue the skb into a different class as indicated by the parents' defmap entry for TC_PRIO_BESTEFFORT. [ i.e. we behave as if tc_classify returned TC_ACT_RECLASSIFY ]. This feature, which isn't documented or implemented in iproute2, and isn't implemented consistently (most qdiscs like sfq, codel, etc drop right away instead of attempting this reclassification) is the sole reason for the reshape_fail and __parent member in Qdisc struct. So remove TCA_CBQ_POLICE support from the kernel, reject it via EOPNOTSUPP so userspace knows we don't support it, and then remove no-longer needed infrastructure in followup commit. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07net: sched: fix tc_should_offload for specific clsact classesDaniel Borkmann
When offloading classifiers such as u32 or flower to hardware, and the qdisc is clsact (TC_H_CLSACT), then we need to differentiate its classes, since not all of them handle ingress, therefore we must leave those in software path. Add a .tcf_cl_offload() callback, so we can generically handle them, tested on ixgbe. Fixes: 10cbc6843446 ("net/sched: cls_flower: Hardware offloaded filters statistics support") Fixes: 5b33f48842fa ("net/flower: Introduce hardware offload support") Fixes: a1b7c5fd7fe9 ("net: sched: add cls_u32 offload hooks for netdevs") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07net: sched: do not acquire qdisc spinlock in qdisc/class stats dumpEric Dumazet
Large tc dumps (tc -s {qdisc|class} sh dev ethX) done by Google BwE host agent [1] are problematic at scale : For each qdisc/class found in the dump, we currently lock the root qdisc spinlock in order to get stats. Sampling stats every 5 seconds from thousands of HTB classes is a challenge when the root qdisc spinlock is under high pressure. Not only the dumps take time, they also slow down the fast path (queue/dequeue packets) by 10 % to 20 % in some cases. An audit of existing qdiscs showed that sch_fq_codel is the only qdisc that might need the qdisc lock in fq_codel_dump_stats() and fq_codel_dump_class_stats() In v2 of this patch, I now use the Qdisc running seqcount to provide consistent reads of packets/bytes counters, regardless of 32/64 bit arches. I also changed rate estimators to use the same infrastructure so that they no longer need to lock root qdisc lock. [1] http://static.googleusercontent.com/media/research.google.com/en//pubs/archive/43838.pdf Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Kevin Athey <kda@google.com> Cc: Xiaotian Pei <xiaotian@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07net_sched: transform qdisc running bit into a seqcountEric Dumazet
Instead of using a single bit (__QDISC___STATE_RUNNING) in sch->__state, use a seqcount. This adds lockdep support, but more importantly it will allow us to sample qdisc/class statistics without having to grab qdisc root lock. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-06net_sched: keep backlog updated with qlenWANG Cong
For gso_skb we only update qlen, backlog should be updated too. Note, it is correct to just update these stats at one layer, because the gso_skb is cached there. Reported-by: Stas Nichiporovich <stasn77@gmail.com> Fixes: 2ccccf5fb43f ("net_sched: update hierarchical backlog too") Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-16net/sched: Enable netdev drivers to update statistics of offloaded actionsAmir Vadai
Introduce stats_update callback. netdev driver could call it for offloaded actions to update the basic statistics (packets, bytes and last use). Since bstats_update() and bstats_cpu_update() use skb as an argument to get the counters, _bstats_update() and _bstats_cpu_update(), that get bytes and packets as arguments, were added. Signed-off-by: Amir Vadai <amirva@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-03net: sched: use pfifo_fast for non real queuesEric Dumazet
Some devices declare a high number of TX queues, then set a much lower real_num_tx_queues This cause setups using fq_codel, sfq or fq as the default qdisc to consume more memory than really needed. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-29net_sched: update hierarchical backlog tooWANG Cong
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>
2016-02-29net_sched: introduce qdisc_replace() helperWANG Cong
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>
2016-01-10net, sched: add skb_at_tc_ingress helperDaniel Borkmann
Add a skb_at_tc_ingress() as this will be needed elsewhere as well and can hide the ugly ifdef. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03net_sched: fix qdisc_tree_decrease_qlen() racesEric Dumazet
qdisc_tree_decrease_qlen() suffers from two problems on multiqueue devices. One problem is that it updates sch->q.qlen and sch->qstats.drops on the mq/mqprio root qdisc, while it should not : Daniele reported underflows errors : [ 681.774821] PAX: sch->q.qlen: 0 n: 1 [ 681.774825] PAX: size overflow detected in function qdisc_tree_decrease_qlen net/sched/sch_api.c:769 cicus.693_49 min, count: 72, decl: qlen; num: 0; context: sk_buff_head; [ 681.774954] CPU: 2 PID: 19 Comm: ksoftirqd/2 Tainted: G O 4.2.6.201511282239-1-grsec #1 [ 681.774955] Hardware name: ASUSTeK COMPUTER INC. X302LJ/X302LJ, BIOS X302LJ.202 03/05/2015 [ 681.774956] ffffffffa9a04863 0000000000000000 0000000000000000 ffffffffa990ff7c [ 681.774959] ffffc90000d3bc38 ffffffffa95d2810 0000000000000007 ffffffffa991002b [ 681.774960] ffffc90000d3bc68 ffffffffa91a44f4 0000000000000001 0000000000000001 [ 681.774962] Call Trace: [ 681.774967] [<ffffffffa95d2810>] dump_stack+0x4c/0x7f [ 681.774970] [<ffffffffa91a44f4>] report_size_overflow+0x34/0x50 [ 681.774972] [<ffffffffa94d17e2>] qdisc_tree_decrease_qlen+0x152/0x160 [ 681.774976] [<ffffffffc02694b1>] fq_codel_dequeue+0x7b1/0x820 [sch_fq_codel] [ 681.774978] [<ffffffffc02680a0>] ? qdisc_peek_dequeued+0xa0/0xa0 [sch_fq_codel] [ 681.774980] [<ffffffffa94cd92d>] __qdisc_run+0x4d/0x1d0 [ 681.774983] [<ffffffffa949b2b2>] net_tx_action+0xc2/0x160 [ 681.774985] [<ffffffffa90664c1>] __do_softirq+0xf1/0x200 [ 681.774987] [<ffffffffa90665ee>] run_ksoftirqd+0x1e/0x30 [ 681.774989] [<ffffffffa90896b0>] smpboot_thread_fn+0x150/0x260 [ 681.774991] [<ffffffffa9089560>] ? sort_range+0x40/0x40 [ 681.774992] [<ffffffffa9085fe4>] kthread+0xe4/0x100 [ 681.774994] [<ffffffffa9085f00>] ? kthread_worker_fn+0x170/0x170 [ 681.774995] [<ffffffffa95d8d1e>] ret_from_fork+0x3e/0x70 mq/mqprio have their own ways to report qlen/drops by folding stats on all their queues, with appropriate locking. A second problem is that qdisc_tree_decrease_qlen() calls qdisc_lookup() without proper locking : concurrent qdisc updates could corrupt the list that qdisc_match_from_root() parses to find a qdisc given its handle. Fix first problem adding a TCQ_F_NOPARENT qdisc flag that qdisc_tree_decrease_qlen() can use to abort its tree traversal, as soon as it meets a mq/mqprio qdisc children. Second problem can be fixed by RCU protection. Qdisc are already freed after RCU grace period, so qdisc_list_add() and qdisc_list_del() simply have to use appropriate rcu list variants. A future patch will add a per struct netdev_queue list anchor, so that qdisc_tree_decrease_qlen() can have more efficient lookups. Reported-by: Daniele Fucini <dfucini@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Cong Wang <cwang@twopensource.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-17bpf: add bpf_redirect() helperAlexei Starovoitov
Existing bpf_clone_redirect() helper clones skb before redirecting it to RX or TX of destination netdev. Introduce bpf_redirect() helper that does that without cloning. Benchmarked with two hosts using 10G ixgbe NICs. One host is doing line rate pktgen. Another host is configured as: $ tc qdisc add dev $dev ingress $ tc filter add dev $dev root pref 10 u32 match u32 0 0 flowid 1:2 \ action bpf run object-file tcbpf1_kern.o section clone_redirect_xmit drop so it receives the packet on $dev and immediately xmits it on $dev + 1 The section 'clone_redirect_xmit' in tcbpf1_kern.o file has the program that does bpf_clone_redirect() and performance is 2.0 Mpps $ tc filter add dev $dev root pref 10 u32 match u32 0 0 flowid 1:2 \ action bpf run object-file tcbpf1_kern.o section redirect_xmit drop which is using bpf_redirect() - 2.4 Mpps and using cls_bpf with integrated actions as: $ tc filter add dev $dev root pref 10 \ bpf run object-file tcbpf1_kern.o section redirect_xmit integ_act classid 1 performance is 2.5 Mpps To summarize: u32+act_bpf using clone_redirect - 2.0 Mpps u32+act_bpf using redirect - 2.4 Mpps cls_bpf using redirect - 2.5 Mpps For comparison linux bridge in this setup is doing 2.1 Mpps and ixgbe rx + drop in ip_rcv - 7.8 Mpps Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-17cls_bpf: introduce integrated actionsDaniel Borkmann
Often cls_bpf classifier is used with single action drop attached. Optimize this use case and let cls_bpf return both classid and action. For backwards compatibility reasons enable this feature under TCA_BPF_FLAG_ACT_DIRECT flag. Then more interesting programs like the following are easier to write: int cls_bpf_prog(struct __sk_buff *skb) { /* classify arp, ip, ipv6 into different traffic classes * and drop all other packets */ switch (skb->protocol) { case htons(ETH_P_ARP): skb->tc_classid = 1; break; case htons(ETH_P_IP): skb->tc_classid = 2; break; case htons(ETH_P_IPV6): skb->tc_classid = 3; break; default: return TC_ACT_SHOT; } return TC_ACT_OK; } Joint work with Daniel Borkmann. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-27net: sched: register noqueue qdiscPhil Sutter
This way users can attach noqueue just like any other qdisc using tc without having to mess with tx_queue_len first. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-08net: sched: extend percpu stats helpersEric Dumazet
qdisc_bstats_update_cpu() and other helpers were added to support percpu stats for qdisc. We want to add percpu stats for tc action, so this patch add common helpers. qdisc_bstats_update_cpu() is renamed to qdisc_bstats_cpu_update() qdisc_qstats_drop_cpu() is renamed to qdisc_qstats_cpu_drop() Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-13net: sched: use counter to break reclassify loopsFlorian Westphal
Seems all we want here is to avoid endless 'goto reclassify' loop. tc_classify_compat even resets this counter when something other than TC_ACT_RECLASSIFY is returned, so this skb-counter doesn't break hypothetical loops induced by something other than perpetual TC_ACT_RECLASSIFY return values. skb_act_clone is now identical to skb_clone, so just use that. Tested with following (bogus) filter: tc filter add dev eth0 parent ffff: \ protocol ip u32 match u32 0 0 police rate 10Kbit burst \ 64000 mtu 1500 action reclassify Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11net: sched: deprecate enqueue_root()Eric Dumazet
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>
2015-05-02net: sched: remove TC_MUNGED bitsFlorian Westphal
Not used. pedit sets TC_MUNGED when packet content was altered, but all the core does is unset MUNGED again and then set OK2MUNGE. And the latter isn't tested anywhere. So lets remove both TC_MUNGED and TC_OK2MUNGE. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-09net_sched: destroy proto tp when all filters are goneCong Wang
Kernel automatically creates a tp for each (kind, protocol, priority) tuple, which has handle 0, when we add a new filter, but it still is left there after we remove our own, unless we don't specify the handle (literally means all the filters under the tuple). For example this one is left: # tc filter show dev eth0 filter parent 8001: protocol arp pref 49152 basic The user-space is hard to clean up these for kernel because filters like u32 are organized in a complex way. So kernel is responsible to remove it after all filters are gone. Each type of filter has its own way to store the filters, so each type has to provide its way to check if all filters are gone. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <cwang@twopensource.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Jamal Hadi Salim<jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-31net: sched: fix panic in rate estimatorsEric Dumazet
Doing the following commands on a non idle network device panics the box instantly, because cpu_bstats gets overwritten by stats. tc qdisc add dev eth0 root <your_favorite_qdisc> ... some traffic (one packet is enough) ... tc qdisc replace dev eth0 root est 1sec 4sec <your_favorite_qdisc> [ 325.355596] BUG: unable to handle kernel paging request at ffff8841dc5a074c [ 325.362609] IP: [<ffffffff81541c9e>] __gnet_stats_copy_basic+0x3e/0x90 [ 325.369158] PGD 1fa7067 PUD 0 [ 325.372254] Oops: 0000 [#1] SMP [ 325.375514] Modules linked in: ... [ 325.398346] CPU: 13 PID: 14313 Comm: tc Not tainted 3.19.0-smp-DEV #1163 [ 325.412042] task: ffff8800793ab5d0 ti: ffff881ff2fa4000 task.ti: ffff881ff2fa4000 [ 325.419518] RIP: 0010:[<ffffffff81541c9e>] [<ffffffff81541c9e>] __gnet_stats_copy_basic+0x3e/0x90 [ 325.428506] RSP: 0018:ffff881ff2fa7928 EFLAGS: 00010286 [ 325.433824] RAX: 000000000000000c RBX: ffff881ff2fa796c RCX: 000000000000000c [ 325.440988] RDX: ffff8841dc5a0744 RSI: 0000000000000060 RDI: 0000000000000060 [ 325.448120] RBP: ffff881ff2fa7948 R08: ffffffff81cd4f80 R09: 0000000000000000 [ 325.455268] R10: ffff883ff223e400 R11: 0000000000000000 R12: 000000015cba0744 [ 325.462405] R13: ffffffff81cd4f80 R14: ffff883ff223e460 R15: ffff883feea0722c [ 325.469536] FS: 00007f2ee30fa700(0000) GS:ffff88407fa20000(0000) knlGS:0000000000000000 [ 325.477630] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 325.483380] CR2: ffff8841dc5a074c CR3: 0000003feeae9000 CR4: 00000000001407e0 [ 325.490510] Stack: [ 325.492524] ffff883feea0722c ffff883fef719dc0 ffff883feea0722c ffff883ff223e4a0 [ 325.499990] ffff881ff2fa79a8 ffffffff815424ee ffff883ff223e49c 000000015cba0744 [ 325.507460] 00000000f2fa7978 0000000000000000 ffff881ff2fa79a8 ffff883ff223e4a0 [ 325.514956] Call Trace: [ 325.517412] [<ffffffff815424ee>] gen_new_estimator+0x8e/0x230 [ 325.523250] [<ffffffff815427aa>] gen_replace_estimator+0x4a/0x60 [ 325.529349] [<ffffffff815718ab>] tc_modify_qdisc+0x52b/0x590 [ 325.535117] [<ffffffff8155edd0>] rtnetlink_rcv_msg+0xa0/0x240 [ 325.540963] [<ffffffff8155ed30>] ? __rtnl_unlock+0x20/0x20 [ 325.546532] [<ffffffff8157f811>] netlink_rcv_skb+0xb1/0xc0 [ 325.552145] [<ffffffff8155b355>] rtnetlink_rcv+0x25/0x40 [ 325.557558] [<ffffffff8157f0d8>] netlink_unicast+0x168/0x220 [ 325.563317] [<ffffffff8157f47c>] netlink_sendmsg+0x2ec/0x3e0 Lets play safe and not use an union : percpu 'pointers' are mostly read anyway, and we have typically few qdiscs per host. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: John Fastabend <john.fastabend@gmail.com> Fixes: 22e0f8b9322c ("net: sched: make bstats per cpu and estimator RCU safe") Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-09net: sched: cls: remove unused op put from tcf_proto_opsJiri Pirko
It is never called and implementations are void. So just remove it. Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-03qdisc: bulk dequeue support for qdiscs with TCQ_F_ONETXQUEUEJesper Dangaard Brouer
Based on DaveM's recent API work on dev_hard_start_xmit(), that allows sending/processing an entire skb list. This patch implements qdisc bulk dequeue, by allowing multiple packets to be dequeued in dequeue_skb(). The optimization principle for this is two fold, (1) to amortize locking cost and (2) avoid expensive tailptr update for notifying HW. (1) Several packets are dequeued while holding the qdisc root_lock, amortizing locking cost over several packet. The dequeued SKB list is processed under the TXQ lock in dev_hard_start_xmit(), thus also amortizing the cost of the TXQ lock. (2) Further more, dev_hard_start_xmit() will utilize the skb->xmit_more API to delay HW tailptr update, which also reduces the cost per packet. One restriction of the new API is that every SKB must belong to the same TXQ. This patch takes the easy way out, by restricting bulk dequeue to qdisc's with the TCQ_F_ONETXQUEUE flag, that specifies the qdisc only have attached a single TXQ. Some detail about the flow; dev_hard_start_xmit() will process the skb list, and transmit packets individually towards the driver (see xmit_one()). In case the driver stops midway in the list, the remaining skb list is returned by dev_hard_start_xmit(). In sch_direct_xmit() this returned list is requeued by dev_requeue_skb(). To avoid overshooting the HW limits, which results in requeuing, the patch limits the amount of bytes dequeued, based on the drivers BQL limits. In-effect bulking will only happen for BQL enabled drivers. Small amounts for extra HoL blocking (2x MTU/0.24ms) were measured at 100Mbit/s, with bulking 8 packets, but the oscillating nature of the measurement indicate something, like sched latency might be causing this effect. More comparisons show, that this oscillation goes away occationally. Thus, we disregard this artifact completely and remove any "magic" bulking limit. For now, as a conservative approach, stop bulking when seeing TSO and segmented GSO packets. They already benefit from bulking on their own. A followup patch add this, to allow easier bisect-ability for finding regressions. Jointed work with Hannes, Daniel and Florian. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-30net: sched: enable per cpu qstatsJohn Fastabend
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>
2014-09-30net: sched: implement qstat helper routinesJohn Fastabend
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>
2014-09-30net: sched: make bstats per cpu and estimator RCU safeJohn Fastabend
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>
2014-09-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: arch/mips/net/bpf_jit.c drivers/net/can/flexcan.c Both the flexcan and MIPS bpf_jit conflicts were cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-22net: sched: shrink struct qdisc_skb_cb to 28 bytesEric Dumazet
We cannot make struct qdisc_skb_cb bigger without impacting IPoIB, or increasing skb->cb[] size. Commit e0f31d849867 ("flow_keys: Record IP layer protocol in skb_flow_dissect()") broke IPoIB. Only current offender is sch_choke, and this one do not need an absolutely precise flow key. If we store 17 bytes of flow key, its more than enough. (Its the actual size of flow_keys if it was a packed structure, but we might add new fields at the end of it later) Signed-off-by: Eric Dumazet <edumazet@google.com> Fixes: e0f31d849867 ("flow_keys: Record IP layer protocol in skb_flow_dissect()") Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-13net: rcu-ify tcf_protoJohn Fastabend
rcu'ify tcf_proto this allows calling tc_classify() without holding any locks. Updaters are protected by RTNL. This patch prepares the core net_sched infrastracture for running the classifier/action chains without holding the qdisc lock however it does nothing to ensure cls_xxx and act_xxx types also work without locking. Additional patches are required to address the fall out. 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>
2014-09-13net: qdisc: use rcu prefix and silence sparse warningsJohn Fastabend
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>
2014-06-23flow_keys: Record IP layer protocol in skb_flow_dissect()Govindarajulu Varadarajan
skb_flow_dissect() dissects only transport header type in ip_proto. It dose not give any information about IPv4 or IPv6. This patch adds new member, n_proto, to struct flow_keys. Which records the IP layer type. i.e IPv4 or IPv6. This can be used in netdev->ndo_rx_flow_steer driver function to dissect flow. Adding new member to flow_keys increases the struct size by around 4 bytes. This causes BUILD_BUG_ON(sizeof(qcb->data) < sz); to fail in qdisc_cb_private_validate() So increase data size by 4 Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-27sched, cls: check if we could overwrite actions when changing a filterCong Wang
When actions are attached to a filter, they are a part of the filter itself, so when changing a filter we should allow to overwrite the actions inside as well. In my specific case, when I tried to _append_ a new action to an existing filter which already has an action, I got EEXIST since kernel refused to overwrite the existing one in kernel. This patch checks if we are changing the filter checking NLM_F_CREATE flag (Sigh, filters don't use NLM_F_REPLACE...) and then passes the boolean down to actions. This fixes the problem above. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Cong Wang <cwang@twopensource.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-13net_sched: add struct net pointer to tcf_proto_ops->dumpWANG Cong
It will be needed by the next patch. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-18net_sched: convert tcf_proto_ops to use struct list_headWANG Cong
We don't need to maintain our own singly linked list code. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-20net_sched: add u64 rate to psched_ratecfg_precompute()Eric Dumazet
Add an extra u64 rate parameter to psched_ratecfg_precompute() so that some qdisc can opt-in for 64bit rates in the future, to overcome the ~34 Gbits limit. psched_ratecfg_getrate() reports a legacy structure to tc utility, so if actual rate is above the 32bit rate field, cap it to the 34Gbit limit. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-31qdisc: make args to qdisc_create_default conststephen hemminger
Fixes warnings introduced by the qdisc default patch. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-31qdisc: allow setting default queuing disciplinestephen hemminger
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>
2013-08-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller