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path: root/include/net/sch_generic.h
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2012-12-12pkt_sched: avoid requeues if possibleEric Dumazet
With BQL being deployed, we can more likely have following behavior : We dequeue a packet from qdisc in dequeue_skb(), then we realize target tx queue is in XOFF state in sch_direct_xmit(), and we have to hold the skb into gso_skb for later. This shows in stats (tc -s qdisc dev eth0) as requeues. Problem of these requeues is that high priority packets can not be dequeued as long as this (possibly low prio and big TSO packet) is not removed from gso_skb. At 1Gbps speed, a full size TSO packet is 500 us of extra latency. In some cases, we know that all packets dequeued from a qdisc are for a particular and known txq : - If device is non multi queue - For all MQ/MQPRIO slave qdiscs This patch introduces a new qdisc flag, TCQ_F_ONETXQUEUE to mark this capability, so that dequeue_skb() is allowed to dequeue a packet only if the associated txq is not stopped. This indeed reduce latencies for high prio packets (or improve fairness with sfq/fq_codel), and almost remove qdisc 'requeues'. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-15net sched: Pass the skb into change so it can access NETLINK_CBEric W. Biederman
cls_flow.c plays with uids and gids. Unless I misread that code it is possible for classifiers to depend on the specific uid and gid values. Therefore I need to know the user namespace of the netlink socket that is installing the packet classifiers. Pass in the rtnetlink skb so I can access the NETLINK_CB of the passed packet. In particular I want access to sk_user_ns(NETLINK_CB(in_skb).ssk). Pass in not the user namespace but the incomming rtnetlink skb into the the classifier change routines as that is generally the more useful parameter. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-07-20net: rename bond_queue_mapping to slave_dev_queue_mappingJiri Pirko
As this is going to be used not only by bonding. Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-12bonding: Fix corrupted queue_mappingEric Dumazet
In the transmit path of the bonding driver, skb->cb is used to stash the skb->queue_mapping so that the bonding device can set its own queue mapping. This value becomes corrupted since the skb->cb is also used in __dev_xmit_skb. When transmitting through bonding driver, bond_select_queue is called from dev_queue_xmit. In bond_select_queue the original skb->queue_mapping is copied into skb->cb (via bond_queue_mapping) and skb->queue_mapping is overwritten with the bond driver queue. Subsequently in dev_queue_xmit, __dev_xmit_skb is called which writes the packet length into skb->cb, thereby overwriting the stashed queue mappping. In bond_dev_queue_xmit (called from hard_start_xmit), the queue mapping for the skb is set to the stashed value which is now the skb length and hence is an invalid queue for the slave device. If we want to save skb->queue_mapping into skb->cb[], best place is to add a field in struct qdisc_skb_cb, to make sure it wont conflict with other layers (eg : Qdiscc, Infiniband...) This patchs also makes sure (struct qdisc_skb_cb)->data is aligned on 8 bytes : netem qdisc for example assumes it can store an u64 in it, without misalignment penalty. Note : we only have 20 bytes left in (struct qdisc_skb_cb)->data[]. The largest user is CHOKe and it fills it. Based on a previous patch from Tom Herbert. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Tom Herbert <therbert@google.com> Cc: John Fastabend <john.r.fastabend@intel.com> Cc: Roland Dreier <roland@kernel.org> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-09net: Make qdisc_skb_cb upper size bound explicit.David S. Miller
Just like skb->cb[], so that qdisc_skb_cb can be encapsulated inside of other data structures. This is intended to be used by IPoIB so that it can remember addressing information stored at hard_header_ops->create() time that it can fetch when the packet gets to the transmit routine. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-31net: sch_generic remove redundant use of <linux/module.h>Paul Gortmaker
This file has modular references, but they are limited to those which are covered by the simple "struct module;" declaration used in dozens of other places. In fact that declaration is already there (just outside of the context of this commit) so simply remove the include line. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-20net: constify skbuff and Qdisc elementsEric Dumazet
Preliminary patch before tcp constification Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-06net: sched: constify tcf_proto and tc_actionEric Dumazet
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-24net_sched: fix THROTTLED/RUNNING raceEric Dumazet
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>
2011-03-04Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/bnx2x/bnx2x.h
2011-03-03net_sched: reduce fifo qdisc sizeEric Dumazet
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>
2011-02-23net_sched: long word align struct qdisc_skb_cb dataEric Dumazet
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>
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
2011-01-21net_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>
2011-01-21net_sched: RCU conversion of stabEric Dumazet
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>
2011-01-21net_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>
2011-01-11net_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>
2010-12-20Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
2010-12-20net_sched: always clone skbsChangli Gao
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>
2010-12-16net: factorize sync-rcu call in unregister_netdevice_manyOctavian Purdila
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>
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>
2010-09-23net: return operator cleanupEric Dumazet
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>
2010-07-07Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
2010-07-03net: decreasing real_num_tx_queues needs to flush qdiscJohn Fastabend
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>
2010-07-03sched: qdisc_reset_all_tx is calling qdisc_reset without qdisc_lockJohn Fastabend
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>
2010-06-29act_mirred: don't clone skb when skb isn't sharedChangli Gao
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>
2010-06-02net: add additional lock to qdisc to increase throughputEric Dumazet
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>
2010-06-02net: QDISC_STATE_RUNNING dont need atomic bit opsEric Dumazet
__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>
2010-06-02net: Define accessors to manipulate QDISC_STATE_RUNNINGEric Dumazet
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>
2010-04-02gen_estimator: deadlock fixEric Dumazet
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>
2010-01-29sched: add head drop fifo queueHagen Paul Pfeifer
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>
2009-11-04net: cleanup include/netEric Dumazet
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>
2009-09-15pkt_sched: Fix tx queue selection in tc_modify_qdiscJarek Poplawski
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>
2009-09-10net_sched: fix estimator lock selection for mq child qdiscsPatrick McHardy
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>
2009-09-06net_sched: add classful multiqueue dummy schedulerDavid S. Miller
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>
2009-09-06net_sched: move dev_graft_qdisc() to sch_generic.cPatrick McHardy
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>
2009-09-02Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/yellowfin.c
2009-08-18net: 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>
2009-08-07net: Avoid enqueuing skb for default qdiscsKrishna Kumar
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>
2009-03-20net: reorder struct Qdisc for better SMP performanceEric Dumazet
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>
2009-02-01pkt_sched: sch_hfsc: sch_htb: Add non-work-conserving warning handler.Jarek Poplawski
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>
2008-11-14pkt_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>
2008-11-06pkt_sched: Fix qdisc len in qdisc_peek_dequeued()Jarek Poplawski
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>
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>
2008-10-31pkt_sched: Add ->peek() methods for fifo, prio and SFQ qdiscs.Patrick McHardy
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>
2008-10-31pkt_sched: sch_generic: Add Qdisc_ops peek() method.Jarek Poplawski
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>
2008-10-06pkt_sched: Fix handling of gso skbs on requeuingJarek Poplawski
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>
2008-09-23pkt_sched: Make qdisc->gso_skb a list.David S. Miller
The idea is that we can use this to get rid of ->requeue(). Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-27pkt_sched: Fix sch_tree_lock()Jarek Poplawski
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>
2008-08-27pkt_sched: Fix gen_estimator locksJarek Poplawski
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>