kernel/linux.git/include/net/sch_generic.h, branch v3.18.94

net_sched: fix order of queue length updates in qdisc_replace()

2017-08-30T08:16:54+00:00

[ Upstream commit 68a66d149a8c78ec6720f268597302883e48e9fa ] This important to call qdisc_tree_reduce_backlog() after changing queue length. Parent qdisc should deactivate class in ->qlen_notify() called from qdisc_tree_reduce_backlog() but this happens only if qdisc->q.qlen in zero. Missed class deactivations leads to crashes/warnings at picking packets from empty qdisc and corrupting state at reactivating this class in future. Signed-off-by: Konstantin Khlebnikov Fixes: 86a7996cc8a0 ("net_sched: introduce qdisc_replace() helper") Acked-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net_sched: update hierarchical backlog too

2016-07-12T12:48:11+00:00

[ Upstream commit 2ccccf5fb43ff62b2b96cc58d95fc0b3596516e4 ] 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 Acked-by: Jamal Hadi Salim Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net_sched: introduce qdisc_replace() helper

2016-07-12T12:48:10+00:00

[ Upstream commit 86a7996cc8a078793670d82ed97d5a99bb4e8496 ] Remove nearly duplicated code and prepare for the following patch. Cc: Jamal Hadi Salim Acked-by: Jamal Hadi Salim Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: sched: fix panic in rate estimators

2015-02-27T01:49:02+00:00

[ Upstream commit 0d32ef8cef9aa8f375e128f78b77caceaa7e8da0 ] Doing the following commands on a non idle network device panics the box instantly, because cpu_bstats gets overwritten by stats. tc qdisc add dev eth0 root ... some traffic (one packet is enough) ... tc qdisc replace dev eth0 root est 1sec 4sec [ 325.355596] BUG: unable to handle kernel paging request at ffff8841dc5a074c [ 325.362609] IP: [] __gnet_stats_copy_basic+0x3e/0x90 [ 325.369158] PGD 1fa7067 PUD 0 [ 325.372254] Oops: 0000 [#1] SMP [ 325.375514] Modules linked in: ... [ 325.398346] CPU: 13 PID: 14313 Comm: tc Not tainted 3.19.0-smp-DEV #1163 [ 325.412042] task: ffff8800793ab5d0 ti: ffff881ff2fa4000 task.ti: ffff881ff2fa4000 [ 325.419518] RIP: 0010:[] [] __gnet_stats_copy_basic+0x3e/0x90 [ 325.428506] RSP: 0018:ffff881ff2fa7928 EFLAGS: 00010286 [ 325.433824] RAX: 000000000000000c RBX: ffff881ff2fa796c RCX: 000000000000000c [ 325.440988] RDX: ffff8841dc5a0744 RSI: 0000000000000060 RDI: 0000000000000060 [ 325.448120] RBP: ffff881ff2fa7948 R08: ffffffff81cd4f80 R09: 0000000000000000 [ 325.455268] R10: ffff883ff223e400 R11: 0000000000000000 R12: 000000015cba0744 [ 325.462405] R13: ffffffff81cd4f80 R14: ffff883ff223e460 R15: ffff883feea0722c [ 325.469536] FS: 00007f2ee30fa700(0000) GS:ffff88407fa20000(0000) knlGS:0000000000000000 [ 325.477630] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 325.483380] CR2: ffff8841dc5a074c CR3: 0000003feeae9000 CR4: 00000000001407e0 [ 325.490510] Stack: [ 325.492524] ffff883feea0722c ffff883fef719dc0 ffff883feea0722c ffff883ff223e4a0 [ 325.499990] ffff881ff2fa79a8 ffffffff815424ee ffff883ff223e49c 000000015cba0744 [ 325.507460] 00000000f2fa7978 0000000000000000 ffff881ff2fa79a8 ffff883ff223e4a0 [ 325.514956] Call Trace: [ 325.517412] [] gen_new_estimator+0x8e/0x230 [ 325.523250] [] gen_replace_estimator+0x4a/0x60 [ 325.529349] [] tc_modify_qdisc+0x52b/0x590 [ 325.535117] [] rtnetlink_rcv_msg+0xa0/0x240 [ 325.540963] [] ? __rtnl_unlock+0x20/0x20 [ 325.546532] [] netlink_rcv_skb+0xb1/0xc0 [ 325.552145] [] rtnetlink_rcv+0x25/0x40 [ 325.557558] [] netlink_unicast+0x168/0x220 [ 325.563317] [] netlink_sendmsg+0x2ec/0x3e0 Lets play safe and not use an union : percpu 'pointers' are mostly read anyway, and we have typically few qdiscs per host. Signed-off-by: Eric Dumazet Cc: John Fastabend Fixes: 22e0f8b9322c ("net: sched: make bstats per cpu and estimator RCU safe") Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

qdisc: bulk dequeue support for qdiscs with TCQ_F_ONETXQUEUE

2014-10-03T19:37:06+00:00

Based on DaveM's recent API work on dev_hard_start_xmit(), that allows sending/processing an entire skb list. This patch implements qdisc bulk dequeue, by allowing multiple packets to be dequeued in dequeue_skb(). The optimization principle for this is two fold, (1) to amortize locking cost and (2) avoid expensive tailptr update for notifying HW. (1) Several packets are dequeued while holding the qdisc root_lock, amortizing locking cost over several packet. The dequeued SKB list is processed under the TXQ lock in dev_hard_start_xmit(), thus also amortizing the cost of the TXQ lock. (2) Further more, dev_hard_start_xmit() will utilize the skb->xmit_more API to delay HW tailptr update, which also reduces the cost per packet. One restriction of the new API is that every SKB must belong to the same TXQ. This patch takes the easy way out, by restricting bulk dequeue to qdisc's with the TCQ_F_ONETXQUEUE flag, that specifies the qdisc only have attached a single TXQ. Some detail about the flow; dev_hard_start_xmit() will process the skb list, and transmit packets individually towards the driver (see xmit_one()). In case the driver stops midway in the list, the remaining skb list is returned by dev_hard_start_xmit(). In sch_direct_xmit() this returned list is requeued by dev_requeue_skb(). To avoid overshooting the HW limits, which results in requeuing, the patch limits the amount of bytes dequeued, based on the drivers BQL limits. In-effect bulking will only happen for BQL enabled drivers. Small amounts for extra HoL blocking (2x MTU/0.24ms) were measured at 100Mbit/s, with bulking 8 packets, but the oscillating nature of the measurement indicate something, like sched latency might be causing this effect. More comparisons show, that this oscillation goes away occationally. Thus, we disregard this artifact completely and remove any "magic" bulking limit. For now, as a conservative approach, stop bulking when seeing TSO and segmented GSO packets. They already benefit from bulking on their own. A followup patch add this, to allow easier bisect-ability for finding regressions. Jointed work with Hannes, Daniel and Florian. Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Hannes Frederic Sowa Signed-off-by: Daniel Borkmann Signed-off-by: Florian Westphal Signed-off-by: David S. Miller

net: sched: enable per cpu qstats

2014-09-30T05:02:26+00:00

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 Signed-off-by: David S. Miller

net: sched: implement qstat helper routines

2014-09-30T05:02:26+00:00

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 Signed-off-by: David S. Miller

net: sched: make bstats per cpu and estimator RCU safe

2014-09-30T05:02:26+00:00

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 Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2014-09-23T16:09:27+00:00

Conflicts: arch/mips/net/bpf_jit.c drivers/net/can/flexcan.c Both the flexcan and MIPS bpf_jit conflicts were cases of simple overlapping changes. Signed-off-by: David S. Miller

net: sched: shrink struct qdisc_skb_cb to 28 bytes

2014-09-22T18:21:47+00:00

We cannot make struct qdisc_skb_cb bigger without impacting IPoIB, or increasing skb->cb[] size. Commit e0f31d849867 ("flow_keys: Record IP layer protocol in skb_flow_dissect()") broke IPoIB. Only current offender is sch_choke, and this one do not need an absolutely precise flow key. If we store 17 bytes of flow key, its more than enough. (Its the actual size of flow_keys if it was a packed structure, but we might add new fields at the end of it later) Signed-off-by: Eric Dumazet Fixes: e0f31d849867 ("flow_keys: Record IP layer protocol in skb_flow_dissect()") Signed-off-by: David S. Miller