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* net_sched: fix THROTTLED/RUNNING raceEric Dumazet2011-03-241-4/+4
| | | | | | | | | | | | | | | | | | | | commit fd245a4adb52 (net_sched: move TCQ_F_THROTTLED flag) added a race. qdisc_watchdog() is run from softirq, so special care should be taken or we can lose one state transition (THROTTLED/RUNNING) Prior to fd245a4adb52, we were manipulating q->flags (qdisc->flags &= ~TCQ_F_THROTTLED;) and this manipulation could only race with qdisc_warn_nonwc(). Since we want to avoid atomic ops in qdisc fast path - it was the meaning of commit 371121057607e (QDISC_STATE_RUNNING dont need atomic bit ops) - fix is to move THROTTLE bit into 'state' field, this one being manipulated with SMP and IRQ safe operations. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'master' of ↵David S. Miller2011-03-031-1/+1
|\ | | | | | | | | | | | | master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/bnx2x/bnx2x.h
| * net_sched: long word align struct qdisc_skb_cb dataEric Dumazet2011-02-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | netem_skb_cb() does : return (struct netem_skb_cb *)qdisc_skb_cb(skb)->data; Unfortunatly struct qdisc_skb_cb data is not long word aligned, so access to psched_time_t time_to_send uses a non aligned access. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net_sched: reduce fifo qdisc sizeEric Dumazet2011-03-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Because of various alignements [SLUB / qdisc], we use 512 bytes of memory for one {p|b}fifo qdisc, instead of 256 bytes on 64bit arches and 192 bytes on 32bit ones. Move the "u32 limit" inside "struct Qdisc" (no impact on other qdiscs) Change qdisc_alloc(), first trying a regular allocation before an oversized one. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge branch 'master' of ↵David S. Miller2011-01-241-3/+5
|\ \ | |/ | | | | | | | | | | | | | | master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: net/sched/sch_hfsc.c net/sched/sch_htb.c net/sched/sch_tbf.c
| * net_sched: accurate bytes/packets stats/ratesEric Dumazet2011-01-201-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 44b8288308ac9d (net_sched: pfifo_head_drop problem), we fixed a problem with pfifo_head drops that incorrectly decreased sch->bstats.bytes and sch->bstats.packets Several qdiscs (CHOKe, SFQ, pfifo_head, ...) are able to drop a previously enqueued packet, and bstats cannot be changed, so bstats/rates are not accurate (over estimated) This patch changes the qdisc_bstats updates to be done at dequeue() time instead of enqueue() time. bstats counters no longer account for dropped frames, and rates are more correct, since enqueue() bursts dont have effect on dequeue() rate. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net_sched: RCU conversion of stabEric Dumazet2011-01-201-6/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch converts stab qdisc management to RCU, so that we can perform the qdisc_calculate_pkt_len() call before getting qdisc lock. This shortens the lock's held time in __dev_xmit_skb(). This permits more qdiscs to get TCQ_F_CAN_BYPASS status, avoiding lot of cache misses and so reducing latencies. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Patrick McHardy <kaber@trash.net> CC: Jesper Dangaard Brouer <hawk@diku.dk> CC: Jarek Poplawski <jarkao2@gmail.com> CC: Jamal Hadi Salim <hadi@cyberus.ca> CC: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net_sched: move TCQ_F_THROTTLED flagEric Dumazet2011-01-201-10/+28
|/ | | | | | | | | | | | | | | | | | | | | | In commit 371121057607e (net: QDISC_STATE_RUNNING dont need atomic bit ops) I moved QDISC_STATE_RUNNING flag to __state container, located in the cache line containing qdisc lock and often dirtied fields. I now move TCQ_F_THROTTLED bit too, so that we let first cache line read mostly, and shared by all cpus. This should speedup HTB/CBQ for example. Not using test_bit()/__clear_bit()/__test_and_set_bit allows to use an "unsigned int" for __state container, reducing by 8 bytes Qdisc size. Introduce helpers to hide implementation details. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Patrick McHardy <kaber@trash.net> CC: Jesper Dangaard Brouer <hawk@diku.dk> CC: Jarek Poplawski <jarkao2@gmail.com> CC: Jamal Hadi Salim <hadi@cyberus.ca> CC: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: factorize qdisc stats handlingEric Dumazet2011-01-101-6/+14
| | | | | | | | | | | | | | | | | 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>
* Merge branch 'master' of ↵David S. Miller2010-12-201-5/+1
|\ | | | | | | master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
| * net_sched: always clone skbsChangli Gao2010-12-201-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pawel reported a panic related to handling shared skbs in ixgbe incorrectly. So we need to revert my previous patch to work around this bug. Instead of reverting the patch completely, I just revert the essential lines, so we can add the previous optimization back more easily in future. commit 3511c9132f8b1e1b5634e41a3331c44b0c13be70 Author: Changli Gao <xiaosuo@gmail.com> Date: Sat Oct 16 13:04:08 2010 +0000 net_sched: remove the unused parameter of qdisc_create_dflt() Reported-by: Pawel Staszewski <pstaszewski@itcare.pl> Signed-off-by: Changli Gao <xiaosuo@gmail.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: factorize sync-rcu call in unregister_netdevice_manyOctavian Purdila2010-12-161-0/+1
|/ | | | | | | | | | | | | | | | | | Add dev_close_many and dev_deactivate_many to factorize another sync-rcu operation on the netdevice unregister path. $ modprobe dummy numdummies=10000 $ ip link set dev dummy* up $ time rmmod dummy Without the patch With the patch real 0m 24.63s real 0m 5.15s user 0m 0.00s user 0m 0.00s sys 0m 6.05s sys 0m 5.14s Signed-off-by: Octavian Purdila <opurdila@ixiacom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: remove the unused parameter of qdisc_create_dflt()Changli Gao2010-10-211-2/+1
| | | | | | | | The first parameter dev isn't in use in qdisc_create_dflt(). Signed-off-by: Changli Gao <xiaosuo@gmail.com> Acked-by: Jamal Hadi Salim <hadi@cyberus.ca> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: return operator cleanupEric Dumazet2010-09-231-1/+1
| | | | | | | | | Change "return (EXPR);" to "return EXPR;" return is not a function, parentheses are not required. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'master' of ↵David S. Miller2010-07-071-4/+16
|\ | | | | | | master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
| * net: decreasing real_num_tx_queues needs to flush qdiscJohn Fastabend2010-07-021-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reducing real_num_queues needs to flush the qdisc otherwise skbs with queue_mappings greater then real_num_tx_queues can be sent to the underlying driver. The flow for this is, dev_queue_xmit() dev_pick_tx() skb_tx_hash() => hash using real_num_tx_queues skb_set_queue_mapping() ... qdisc_enqueue_root() => enqueue skb on txq from hash ... dev->real_num_tx_queues -= n ... sch_direct_xmit() dev_hard_start_xmit() ndo_start_xmit(skb,dev) => skb queue set with old hash skbs are enqueued on the qdisc with skb->queue_mapping set 0 < queue_mappings < real_num_tx_queues. When the driver decreases real_num_tx_queues skb's may be dequeued from the qdisc with a queue_mapping greater then real_num_tx_queues. This fixes a case in ixgbe where this was occurring with DCB and FCoE. Because the driver is using queue_mapping to map skbs to tx descriptor rings we can potentially map skbs to rings that no longer exist. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Tested-by: Ross Brattain <ross.b.brattain@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * sched: qdisc_reset_all_tx is calling qdisc_reset without qdisc_lockJohn Fastabend2010-07-021-2/+10
| | | | | | | | | | | | | | | | | | | | When calling qdisc_reset() the qdisc lock needs to be held. In this case there is at least one driver i4l which is using this without holding the lock. Add the locking here. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | act_mirred: don't clone skb when skb isn't sharedChangli Gao2010-06-281-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | don't clone skb when skb isn't shared When the tcf_action is TC_ACT_STOLEN, and the skb isn't shared, we don't need to clone a new skb. As the skb will be freed after this function returns, we can use it freely once we get a reference to it. Signed-off-by: Changli Gao <xiaosuo@gmail.com> ---- include/net/sch_generic.h | 11 +++++++++-- net/sched/act_mirred.c | 6 +++--- 2 files changed, 12 insertions(+), 5 deletions(-) Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: add additional lock to qdisc to increase throughputEric Dumazet2010-06-021-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When many cpus compete for sending frames on a given qdisc, the qdisc spinlock suffers from very high contention. The cpu owning __QDISC_STATE_RUNNING bit has same priority to acquire the lock, and cannot dequeue packets fast enough, since it must wait for this lock for each dequeued packet. One solution to this problem is to force all cpus spinning on a second lock before trying to get the main lock, when/if they see __QDISC_STATE_RUNNING already set. The owning cpu then compete with at most one other cpu for the main lock, allowing for higher dequeueing rate. Based on a previous patch from Alexander Duyck. I added the heuristic to avoid the atomic in fast path, and put the new lock far away from the cache line used by the dequeue worker. Also try to release the busylock lock as late as possible. Tests with following script gave a boost from ~50.000 pps to ~600.000 pps on a dual quad core machine (E5450 @3.00GHz), tg3 driver. (A single netperf flow can reach ~800.000 pps on this platform) for j in `seq 0 3`; do for i in `seq 0 7`; do netperf -H 192.168.0.1 -t UDP_STREAM -l 60 -N -T $i -- -m 6 & done done Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: QDISC_STATE_RUNNING dont need atomic bit opsEric Dumazet2010-06-021-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __QDISC_STATE_RUNNING is always changed while qdisc lock is held. We can avoid two atomic operations in xmit path, if we move this bit in a new __state container. Location of this __state container is carefully chosen so that fast path only dirties one qdisc cache line. THROTTLED bit could later be moved into this __state location too, to avoid dirtying first qdisc cache line. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: Define accessors to manipulate QDISC_STATE_RUNNINGEric Dumazet2010-06-021-0/+15
|/ | | | | | | | Define three helpers to manipulate QDISC_STATE_RUNNIG flag, that a second patch will move on another location. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* gen_estimator: deadlock fixEric Dumazet2010-04-011-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | One of my test machine got a deadlock during "tc" sessions, adding/deleting classes & filters, using traffic estimators. After some analysis, I believe we have a potential use after free case in est_timer() : spin_lock(e->stats_lock); << HERE >> read_lock(&est_lock); if (e->bstats == NULL) << TEST >> goto skip; Test is done a bit late, because after estimator is killed, and before rcu grace period elapsed, we might already have freed/reuse memory where e->stats_locks points to (some qdisc->q.lock) A possible fix is to respect a rcu grace period at Qdisc dismantle time. On 64bit, sizeof(struct Qdisc) is exactly 192 bytes. Adding 16 bytes to it (for struct rcu_head) is a problem because it might change performance, given QDISC_ALIGNTO is 32 bytes. This is why I also change QDISC_ALIGNTO to 64 bytes, to satisfy most current alignment requirements. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* sched: add head drop fifo queueHagen Paul Pfeifer2010-01-281-0/+19
| | | | | | | | | | | | | This adds an additional queuing strategy, called pfifo_head_drop, to remove the oldest skb in the case of an overflow within the queue - the head element - instead of the last skb (tail). To remove the oldest skb in congested situations is useful for sensor network environments where newer packets reflect the superior information. Reviewed-by: Florian Westphal <fw@strlen.de> Acked-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: cleanup include/netEric Dumazet2009-11-041-20/+10
| | | | | | | | | | | | | | | This cleanup patch puts struct/union/enum opening braces, in first line to ease grep games. struct something { becomes : struct something { Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: Fix tx queue selection in tc_modify_qdiscJarek Poplawski2009-09-151-1/+1
| | | | | | | | | | | | | | | After the recent mq change there is the new select_queue qdisc class method used in tc_modify_qdisc, but it works OK only for direct child qdiscs of mq qdisc. Grandchildren always get the first tx queue, which would give wrong qdisc_root etc. results (e.g. for sch_htb as child of sch_prio). This patch fixes it by using parent's dev_queue for such grandchildren qdiscs. The select_queue method's return type is changed BTW. With feedback from: Patrick McHardy <kaber@trash.net> Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: fix estimator lock selection for mq child qdiscsPatrick McHardy2009-09-091-0/+1
| | | | | | | | | | | | | | | | | When new child qdiscs are attached to the mq qdisc, they are actually attached as root qdiscs to the device queues. The lock selection for new estimators incorrectly picks the root lock of the existing and to be replaced qdisc, which results in a use-after-free once the old qdisc has been destroyed. Mark mq qdisc instances with a new flag and treat qdiscs attached to mq as children similar to regular root qdiscs. Additionally prevent estimators from being attached to the mq qdisc itself since it only updates its byte and packet counters during dumps. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: add classful multiqueue dummy schedulerDavid S. Miller2009-09-061-0/+4
| | | | | | | | | | | | | | | | | | | This patch adds a classful dummy scheduler which can be used as root qdisc for multiqueue devices and exposes each device queue as a child class. This allows to address queues individually and graft them similar to regular classes. Additionally it presents an accumulated view of the statistics of all real root qdiscs in the dummy root. Two new callbacks are added to the qdisc_ops and qdisc_class_ops: - cl_ops->select_queue selects the tx queue number for new child classes. - qdisc_ops->attach() overrides root qdisc device grafting to attach non-shared qdiscs to the queues. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: move dev_graft_qdisc() to sch_generic.cPatrick McHardy2009-09-061-0/+2
| | | | | | | It will be used in a following patch by the multiqueue qdisc. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'master' of ↵David S. Miller2009-09-021-1/+1
|\ | | | | | | | | | | | | master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/yellowfin.c
| * net: restore gnet_stats_basic to previous definitionEric Dumazet2009-08-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | net: Avoid enqueuing skb for default qdiscsKrishna Kumar2009-08-061-2/+13
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dev_queue_xmit enqueue's a skb and calls qdisc_run which dequeue's the skb and xmits it. In most cases, the skb that is enqueue'd is the same one that is dequeue'd (unless the queue gets stopped or multiple cpu's write to the same queue and ends in a race with qdisc_run). For default qdiscs, we can remove the redundant enqueue/dequeue and simply xmit the skb since the default qdisc is work-conserving. The patch uses a new flag - TCQ_F_CAN_BYPASS to identify the default fast queue. The controversial part of the patch is incrementing qlen when a skb is requeued - this is to avoid checks like the second line below: + } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) && >> !q->gso_skb && + !test_and_set_bit(__QDISC_STATE_RUNNING, &q->state)) { Results of a 2 hour testing for multiple netperf sessions (1, 2, 4, 8, 12 sessions on a 4 cpu system-X). The BW numbers are aggregate Mb/s across iterations tested with this version on System-X boxes with Chelsio 10gbps cards: ---------------------------------- Size | ORG BW NEW BW | ---------------------------------- 128K | 156964 159381 | 256K | 158650 162042 | ---------------------------------- Changes from ver1: 1. Move sch_direct_xmit declaration from sch_generic.h to pkt_sched.h 2. Update qdisc basic statistics for direct xmit path. 3. Set qlen to zero in qdisc_reset. 4. Changed some function names to more meaningful ones. Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: reorder struct Qdisc for better SMP performanceEric Dumazet2009-03-201-9/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dev_queue_xmit() needs to dirty fields "state", "q", "bstats" and "qstats" On x86_64 arch, they currently span three cache lines, involving more cache line ping pongs than necessary, making longer holding of queue spinlock. We can reduce this to one cache line, by grouping all read-mostly fields at the beginning of structure. (Or should I say, all highly modified fields at the end :) ) Before patch : offsetof(struct Qdisc, state)=0x38 offsetof(struct Qdisc, q)=0x48 offsetof(struct Qdisc, bstats)=0x80 offsetof(struct Qdisc, qstats)=0x90 sizeof(struct Qdisc)=0xc8 After patch : offsetof(struct Qdisc, state)=0x80 offsetof(struct Qdisc, q)=0x88 offsetof(struct Qdisc, bstats)=0xa0 offsetof(struct Qdisc, qstats)=0xac sizeof(struct Qdisc)=0xc0 Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: sch_hfsc: sch_htb: Add non-work-conserving warning handler.Jarek Poplawski2009-02-011-3/+4
| | | | | | | | | | | | Patrick McHardy <kaber@trash.net> suggested: > How about making this flag and the warning message (in a out-of-line > function) globally available? Other qdiscs (f.i. HFSC) can't deal with > inner non-work-conserving qdiscs as well. This patch uses qdisc->flags field of "suspected" child qdisc. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: Remove qdisc->ops->requeue() etc.Jarek Poplawski2008-11-131-17/+0
| | | | | | | | | | | | | | 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>
* pkt_sched: Fix qdisc len in qdisc_peek_dequeued()Jarek Poplawski2008-11-051-3/+9
| | | | | | | | | | A packet dequeued and stored as gso_skb in qdisc_peek_dequeued() should be seen as part of the queue for sch->q.qlen queries until it's really dequeued with qdisc_dequeue_peeked(), so qlen needs additional updating in these functions. (Updating qstats.backlog shouldn't matter here.) Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: Add peek emulation for non-work-conserving qdiscs.Jarek Poplawski2008-10-311-0/+23
| | | | | | | | | | | | | | | 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>
* pkt_sched: Add ->peek() methods for fifo, prio and SFQ qdiscs.Patrick McHardy2008-10-311-0/+5
| | | | | | | | | | | | | | | From: Patrick McHardy <kaber@trash.net> Just as a demonstration how easy adding a peek operation to the work-conserving qdiscs actually is. It doesn't need to keep or change any internal state in many cases thanks to the guarantee that the packet will either be dequeued or, if another packet arrives, the upper qdisc will immediately ->peek again to reevaluate the state. (This is only slightly modified Patrick's patch.) Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: sch_generic: Add Qdisc_ops peek() method.Jarek Poplawski2008-10-311-0/+1
| | | | | | | | | | Add Qdisc_ops peek() method in order to replace requeuing. Based on ideas and patches of Herbert Xu, Patrick McHardy and David S. Miller. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: Fix handling of gso skbs on requeuingJarek Poplawski2008-10-061-0/+1
| | | | | | | | | | | Jay Cliburn noticed and diagnosed a bug triggered in dev_gso_skb_destructor() after last change from qdisc->gso_skb to qdisc->requeue list. Since gso_segmented skbs can't be queued to another list this patch brings back qdisc->gso_skb for them. Reported-by: Jay Cliburn <jcliburn@gmail.com> Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: Make qdisc->gso_skb a list.David S. Miller2008-09-221-1/+1
| | | | | | | The idea is that we can use this to get rid of ->requeue(). Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: Fix sch_tree_lock()Jarek Poplawski2008-08-271-2/+2
| | | | | | | | | Use new qdisc_root_sleeping_lock() instead of qdisc_root_lock() as sch_tree_lock() because this lock could be used while dev is deactivated, but we never need to use this with noop_qdisc as a root. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: Fix gen_estimator locksJarek Poplawski2008-08-271-0/+8
| | | | | | | | | | | | While passing a qdisc root lock to gen_new_estimator() and gen_replace_estimator() dev could be deactivated or even before grafting proper root qdisc as qdisc_sleeping (e.g. qdisc_create), so using qdisc_root_lock() is not enough. This patch adds qdisc_root_sleeping_lock() for this, plus additional checks, where necessary. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: Fix qdisc_watchdog() vs. dev_deactivate() raceJarek Poplawski2008-08-211-0/+5
| | | | | | | | | | | | | dev_deactivate() can skip rescheduling of a qdisc by qdisc_watchdog() or other timer calling netif_schedule() after dev_queue_deactivate(). We prevent this checking aliveness before scheduling the timer. Since during deactivation the root qdisc is available only as qdisc_sleeping additional accessor qdisc_root_sleeping() is created. With feedback from Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: No longer destroy qdiscs from RCU.David S. Miller2008-08-171-1/+0
| | | | | | | | | | We can now kill them synchronously with all of the previous dev_deactivate() cures. This makes netdev destruction and shutdown saner as the qdiscs hold references to the device. Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: Add 'deactivated' state.David S. Miller2008-08-171-0/+1
| | | | | | | | | | | | | | | | This new state lets dev_deactivate() mark a qdisc as having been deactivated. dev_queue_xmit() and ing_filter() check for this bit and do not try to process the qdisc if the bit is set. dev_deactivate() polls the qdisc after setting the bit, waiting for both __QDISC_STATE_RUNNING and __QDISC_STATE_SCHED to clear. This isn't perfect yet, but subsequent changesets will make it so. This part is just one piece of the puzzle. Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: Add qdisc __NET_XMIT_BYPASS flagJarek Poplawski2008-08-041-3/+3
| | | | | | | | | | | | Patrick McHardy <kaber@trash.net> noticed that it would be nice to handle NET_XMIT_BYPASS by NET_XMIT_SUCCESS with an internal qdisc flag __NET_XMIT_BYPASS and to remove the mapping from dev_queue_xmit(). David Miller <davem@davemloft.net> spotted a serious bug in the first version of this patch. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: Add qdisc __NET_XMIT_STOLEN flagJarek Poplawski2008-08-041-1/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patrick McHardy <kaber@trash.net> noticed: "The other problem that affects all qdiscs supporting actions is TC_ACT_QUEUED/TC_ACT_STOLEN getting mapped to NET_XMIT_SUCCESS even though the packet is not queued, corrupting upper qdiscs' qlen counters." and later explained: "The reason why it translates it at all seems to be to not increase the drops counter. Within a single qdisc this could be avoided by other means easily, upper qdiscs would still increase the counter when we return anything besides NET_XMIT_SUCCESS though. This means we need a new NET_XMIT return value to indicate this to the upper qdiscs. So I'd suggest to introduce NET_XMIT_STOLEN, return that to upper qdiscs and translate it to NET_XMIT_SUCCESS in dev_queue_xmit, similar to NET_XMIT_BYPASS." David Miller <davem@davemloft.net> noticed: "Maybe these NET_XMIT_* values being passed around should be a set of bits. They could be composed of base meanings, combined with specific attributes. So you could say "NET_XMIT_DROP | __NET_XMIT_NO_DROP_COUNT" The attributes get masked out by the top-level ->enqueue() caller, such that the base meanings are the only thing that make their way up into the stack. If it's only about communication within the qdisc tree, let's simply code it that way." This patch is trying to realize these ideas. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: Make sure RTNL is held in qdisc_root_lock().David S. Miller2008-08-021-0/+12
| | | | | | | | | It is the only legal environment in which this can be used. Add some commentary explaining the situation. Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: Fix build with NET_SCHED disabled.David S. Miller2008-07-201-0/+2
| | | | | | | | | The stab bits can't be referenced uniless the full packet scheduler layer is enabled. Reported by Stephen Rothwell. Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sched: Add size table for qdiscsJussi Kivilinna2008-07-201-1/+24
| | | | | | | | | | | Add size table functions for qdiscs and calculate packet size in qdisc_enqueue(). Based on patch by Patrick McHardy http://marc.info/?l=linux-netdev&m=115201979221729&w=2 Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
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