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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>
2016-06-10net_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>
2016-06-10net_sched: cbq: remove a flaky use of qdisc_is_throttled()Eric Dumazet
So far no qdisc ever unset the throttled bit at enqueue() time, so CBQ usage of qdisc_is_throttled() was flaky. Since __QDISC_STATE_THROTTLED set/unset is way too expensive considering that only CBQ was eventually caring for this status, it would make sense to implement a Qdisc ops ->is_throttled() if we find that this is needed. Signed-off-by: Eric Dumazet <edumazet@google.com> 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>
2016-06-08cbq: 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>
2016-06-08cbq: remove TCA_CBQ_OVL_STRATEGY supportFlorian Westphal
since initial revision of cbq in 2004 iproute 2 has never implemented support for TCA_CBQ_OVL_STRATEGY, which is what needs to be set to activate the class->drop() call (TC_CBQ_OVL_DROP strategy must be set by userspace value must be set by userspace). David Miller says: It seems really safe to kill this thing off, flag an error if someone tries to set the attribute, and therefore kill off all of the non-default cbq_ovl_*() functions. A followup commit can then remove all .drop qdisc methods since this removed the only caller. Signed-off-by: Florian Westphal <fw@strlen.de> 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>
2016-02-29net_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>
2015-08-27net: sched: consolidate tc_classify{,_compat}Daniel Borkmann
For classifiers getting invoked via tc_classify(), we always need an extra function call into tc_classify_compat(), as both are being exported as symbols and tc_classify() itself doesn't do much except handling of reclassifications when tp->classify() returned with TC_ACT_RECLASSIFY. CBQ and ATM are the only qdiscs that directly call into tc_classify_compat(), all others use tc_classify(). When tc actions are being configured out in the kernel, tc_classify() effectively does nothing besides delegating. We could spare this layer and consolidate both functions. pktgen on single CPU constantly pushing skbs directly into the netif_receive_skb() path with a dummy classifier on ingress qdisc attached, improves slightly from 22.3Mpps to 23.1Mpps. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> 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: restrict use of qstats qlenJohn Fastabend
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>
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>
2014-09-26net: sched: use pinned timersEric Dumazet
While using a MQ + NETEM setup, I had confirmation that the default timer migration ( /proc/sys/kernel/timer_migration ) is killing us. Installing this on a receiver side of a TCP_STREAM test, (NIC has 8 TX queues) : EST="est 1sec 4sec" for ETH in eth1 do tc qd del dev $ETH root 2>/dev/null tc qd add dev $ETH root handle 1: mq tc qd add dev $ETH parent 1:1 $EST netem limit 70000 delay 6ms tc qd add dev $ETH parent 1:2 $EST netem limit 70000 delay 8ms tc qd add dev $ETH parent 1:3 $EST netem limit 70000 delay 10ms tc qd add dev $ETH parent 1:4 $EST netem limit 70000 delay 12ms tc qd add dev $ETH parent 1:5 $EST netem limit 70000 delay 14ms tc qd add dev $ETH parent 1:6 $EST netem limit 70000 delay 16ms tc qd add dev $ETH parent 1:7 $EST netem limit 80000 delay 18ms tc qd add dev $ETH parent 1:8 $EST netem limit 90000 delay 20ms done We can see that timers get migrated into a single cpu, presumably idle at the time timers are set up. Then all qdisc dequeues run from this cpu and huge lock contention happens. This single cpu is stuck in softirq mode and cannot dequeue fast enough. 39.24% [kernel] [k] _raw_spin_lock 2.65% [kernel] [k] netem_enqueue 1.80% [kernel] [k] netem_dequeue 1.63% [kernel] [k] copy_user_enhanced_fast_string 1.45% [kernel] [k] _raw_spin_lock_bh By pinning qdisc timers on the cpu running the qdisc, we respect proper XPS setting and remove this lock contention. 5.84% [kernel] [k] netem_enqueue 4.83% [kernel] [k] _raw_spin_lock 2.92% [kernel] [k] copy_user_enhanced_fast_string Current Qdiscs that benefit from this change are : netem, cbq, fq, hfsc, tbf, htb. Signed-off-by: Eric Dumazet <edumazet@google.com> 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>
2014-08-19cbq: now_rt removalVasily Averin
Now q->now_rt is identical to q->now and is not required anymore. Signed-off-by: Vasily Averin <vvs@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-19cbq: incorrectly low bandwidth setting blocks limited trafficVasily Averin
Mainstream commit f0f6ee1f70c4 ("cbq: incorrect processing of high limits") have side effect: if cbq bandwidth setting is less than real interface throughput non-limited traffic can delay limited traffic for a very long time. This happen because of q->now changes incorrectly in cbq_dequeue(): in described scenario L2T is much greater than real time delay, and q->now gets an extra boost for each transmitted packet. Accumulated boost prevents update q->now, and blocked class can wait very long time until (q->now >= cl->undertime) will be true again. To fix the problem the patch updates q->now on each cbq_update() call. L2T-related pre-modification q->now was moved to cbq_update(). My testing confirmed that it fixes the problem and did not discover any side-effects Fixes: f0f6ee1f70c4 ("cbq: incorrect processing of high limits") Signed-off-by: Vasily Averin <vvs@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-13net_sched: return nla_nest_end() instead of skb->lenYang Yingliang
nla_nest_end() already has return skb->len, so replace return skb->len with return nla_nest_end instead(). Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-31net_sched: replace pr_warning with pr_warnYang Yingliang
Prefer pr_warn(... to pr_warning(... Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-19sch_cbq: remove unnecessary null pointer checkYang Yingliang
It already has a NULL pointer check of rtab in qdisc_put_rtab(). Remove the check outside of qdisc_put_rtab(). Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-10net_sched: add space around '>' and before '('Yang Yingliang
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>
2013-07-30net_sched: Fix stack info leak in cbq_dump_wrr().David S. Miller
Make sure the reserved fields, and padding (if any), are fully initialized. Based upon a patch by Dan Carpenter and feedback from Joe Perches. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-11net_sched: add 64bit rate estimatorsEric Dumazet
struct gnet_stats_rate_est contains u32 fields, so the bytes per second field can wrap at 34360Mbit. Add a new gnet_stats_rate_est64 structure to get 64bit bps/pps fields, and switch the kernel to use this structure natively. This structure is dumped to user space as a new attribute : TCA_STATS_RATE_EST64 Old tc command will now display the capped bps (to 34360Mbit), instead of wrapped values, and updated tc command will display correct information. Old tc command output, after patch : eric:~# tc -s -d qd sh dev lo qdisc pfifo 8001: root refcnt 2 limit 1000p Sent 80868245400 bytes 1978837 pkt (dropped 0, overlimits 0 requeues 0) rate 34360Mbit 189696pps backlog 0b 0p requeues 0 This patch carefully reorganizes "struct Qdisc" layout to get optimal performance on SMP. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-02cbq: incorrect processing of high limitsVasily Averin
currently cbq works incorrectly for limits > 10% real link bandwidth, and practically does not work for limits > 50% real link bandwidth. Below are results of experiments taken on 1 Gbit link In shaper | Actual Result -----------+--------------- 100M | 108 Mbps 200M | 244 Mbps 300M | 412 Mbps 500M | 893 Mbps This happen because of q->now changes incorrectly in cbq_dequeue(): when it is called before real end of packet transmitting, L2T is greater than real time delay, q_now gets an extra boost but never compensate it. To fix this problem we prevent change of q->now until its synchronization with real time. Signed-off-by: Vasily Averin <vvs@openvz.org> Reviewed-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-27hlist: drop the node parameter from iteratorsSasha Levin
I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-21pkt_sched: use ns_to_ktime() helperEric Dumazet
ns_to_ktime() seems better than ktime_set() + ktime_add_ns() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-11net-sched: sch_cbq: avoid infinite loopEric Dumazet
Its possible to setup a bad cbq configuration leading to an infinite loop in cbq_classify() DEV_OUT=eth0 ICMP="match ip protocol 1 0xff" U32="protocol ip u32" DST="match ip dst" tc qdisc add dev $DEV_OUT root handle 1: cbq avpkt 1000 \ bandwidth 100mbit tc class add dev $DEV_OUT parent 1: classid 1:1 cbq \ rate 512kbit allot 1500 prio 5 bounded isolated tc filter add dev $DEV_OUT parent 1: prio 3 $U32 \ $ICMP $DST 192.168.3.234 flowid 1: Reported-by: Denys Fedoryschenko <denys@visp.net.lb> Tested-by: Denys Fedoryschenko <denys@visp.net.lb> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-01pkt_sched: Stop using NLA_PUT*().David S. Miller
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>
2011-01-24Merge branch 'master' of ↵David S. Miller
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
2011-01-20net_sched: accurate bytes/packets stats/ratesEric Dumazet
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>
2011-01-20net_sched: move TCQ_F_THROTTLED flagEric Dumazet
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>
2011-01-19net_sched: cleanupsEric Dumazet
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>
2011-01-10net_sched: factorize qdisc stats handlingEric Dumazet
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>
2010-10-21net_sched: remove the unused parameter of qdisc_create_dflt()Changli Gao
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>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
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>
2009-10-07pkt_sched: gen_estimator: Dont report fake rate estimatorsEric Dumazet
Jarek Poplawski a écrit : > > > Hmm... So you made me to do some "real" work here, and guess what?: > there is one serious checkpatch warning! ;-) Plus, this new parameter > should be added to the function description. Otherwise: > Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> > > Thanks, > Jarek P. > > PS: I guess full "Don't" would show we really mean it... Okay :) Here is the last round, before the night ! Thanks again [RFC] pkt_sched: gen_estimator: Don't report fake rate estimators We currently send TCA_STATS_RATE_EST elements to netlink users, even if no estimator is running. # tc -s -d qdisc qdisc pfifo_fast 0: dev eth0 root bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 Sent 112833764978 bytes 1495081739 pkt (dropped 0, overlimits 0 requeues 0) rate 0bit 0pps backlog 0b 0p requeues 0 User has no way to tell if the "rate 0bit 0pps" is a real estimation, or a fake one (because no estimator is active) After this patch, tc command output is : $ tc -s -d qdisc qdisc pfifo_fast 0: dev eth0 root bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 Sent 561075 bytes 1196 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 We add a parameter to gnet_stats_copy_rate_est() function so that it can use gen_estimator_active(bstats, r), as suggested by Jarek. This parameter can be NULL if check is not necessary, (htb for example has a mandatory rate estimator) Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-06net_sched: remove some unnecessary checks in classful schedulersPatrick McHardy
The class argument to the ->graft(), ->leaf(), ->dump(), ->dump_stats() all originate from either ->get() or ->walk() and are always valid. Remove unnecessary checks. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-01pkt_sched: Revert tasklet_hrtimer changes.David S. Miller
These are full of unresolved problems, mainly that conversions don't work 1-1 from hrtimers to tasklet_hrtimers because unlike hrtimers tasklets can't be killed from softirq context. And when a qdisc gets reset, that's exactly what we need to do here. We'll work this out in the net-next-2.6 tree and if warranted we'll backport that work to -stable. This reverts the following 3 changesets: a2cb6a4dd470d7a64255a10b843b0d188416b78f ("pkt_sched: Fix bogon in tasklet_hrtimer changes.") 38acce2d7983632100a9ff3fd20295f6e34074a8 ("pkt_sched: Convert CBQ to tasklet_hrtimer.") ee5f9757ea17759e1ce5503bdae2b07e48e32af9 ("pkt_sched: Convert qdisc_watchdog to tasklet_hrtimer") Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-24pkt_sched: Fix bogon in tasklet_hrtimer changes.David S. Miller
Reported by Stephen Rothwell, luckily it's harmless: net/sched/sch_api.c: In function 'qdisc_watchdog': net/sched/sch_api.c:460: warning: initialization from incompatible pointer type net/sched/sch_cbq.c: In function 'cbq_undelay': net/sched/sch_cbq.c:595: warning: initialization from incompatible pointer type Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-23pkt_sched: Convert CBQ to tasklet_hrtimer.David S. Miller
This code expects to run in softirq context, and bare hrtimers run in hw IRQ context. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Thomas Gleixner <tglx@linutronix.de>
2009-08-17net: restore gnet_stats_basic to previous definitionEric Dumazet
In 5e140dfc1fe87eae27846f193086724806b33c7d "net: reorder struct Qdisc for better SMP performance" the definition of struct gnet_stats_basic changed incompatibly, as copies of this struct are shipped to userland via netlink. Restoring old behavior is not welcome, for performance reason. Fix is to use a private structure for kernel, and teach gnet_stats_copy_basic() to convert from kernel to user land, using legacy structure (struct gnet_stats_basic) Based on a report and initial patch from Michael Spang. Reported-by: Michael Spang <mspang@csclub.uwaterloo.ca> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-15pkt_sched: Rename PSCHED_US2NS and PSCHED_NS2USJarek Poplawski
Let's use TICKS instead of US, so PSCHED_TICKS2NS and PSCHED_NS2TICKS (like in PSCHED_TICKS_PER_SEC already) to avoid misleading. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-15pkt_sched: Change misleading code in class delete.Jarek Poplawski
While looking for a possible reason of bugzilla report on HTB oops: http://bugzilla.kernel.org/show_bug.cgi?id=12858 I found the code in htb_delete calling htb_destroy_class on zero refcount is very misleading: it can suggest this is a common path, and destroy is called under sch_tree_lock. Actually, this can never happen like this because before deletion cops->get() is done, and after delete a class is still used by tclass_notify. The class destroy is always called from cops->put(), so without sch_tree_lock. This doesn't mean much now (since 2.6.27) because all vulnerable calls were moved from htb_destroy_class to htb_delete, but there was a bug in older kernels. The same change is done for other classful scheds, which, it seems, didn't have similar locking problems here. Reported-by: m0sia <m0sia@m0sia.ru> Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25tc: check for errors in gen_rate_estimator creationStephen Hemminger
The functions gen_new_estimator and gen_replace_estimator can return errors, but they were being ignored. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-20pkt_sched: remove unnecessary xchg() in packet schedulersPatrick McHardy
The use of xchg() hasn't been necessary since 2.2.something when proper locking was added to packet schedulers. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-13pkt_sched: Remove qdisc->ops->requeue() etc.Jarek Poplawski
After implementing qdisc->ops->peek() and changing sch_netem into classless qdisc there are no more qdisc->ops->requeue() users. This patch removes this method with its wrappers (qdisc_requeue()), and also unused qdisc->requeue structure. There are a few minor fixes of warnings (htb_enqueue()) and comments btw. The idea to kill ->requeue() and a similar patch were first developed by David S. Miller. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-31pkt_sched: Add peek emulation for non-work-conserving qdiscs.Jarek Poplawski
This patch adds qdisc_peek_dequeued() wrapper to emulate peek method with qdisc->dequeue() and storing "peeked" skb in qdisc->gso_skb until dequeuing. This is mainly for compatibility reasons not to break some strange configs because peeking is expected for non-work-conserving parent qdiscs to query work-conserving child qdiscs. This implementation requires using qdisc_dequeue_peeked() wrapper instead of directly calling qdisc->dequeue() for all qdiscs ever querried with qdisc->ops->peek() or qdisc_peek_dequeued(). Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-05hrtimer: convert net::sched_cbq to the new hrtimer apisArjan van de Ven
In order to be able to do range hrtimers we need to use accessor functions to the "expire" member of the hrtimer struct. This patch converts sched_cbq to these accessors. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-08-29pkt_sched: Fix locking of qdisc_root with qdisc_root_sleeping_lock()Jarek Poplawski
Use qdisc_root_sleeping_lock() instead of qdisc_root_lock() where appropriate. The only difference is while dev is deactivated, when currently we can use a sleeping qdisc with the lock of noop_qdisc. This shouldn't be dangerous since after deactivation root lock could be used only by gen_estimator code, but looks wrong anyway. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>