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2016-09-19sched: replace __skb_dequeue with __qdisc_dequeue_headFlorian Westphal
After previous patch these functions are identical. Replace __skb_dequeue in qdiscs with __qdisc_dequeue_head. Next patch will then make __qdisc_dequeue_head handle single-linked list instead of strcut sk_buff_head argument. Doesn't change generated code. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-19pie: use qdisc_dequeue_head wrapperFlorian Westphal
Doesn't change generated code. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-25net_sched: drop packets after root qdisc lock is releasedEric Dumazet
Qdisc performance suffers when packets are dropped at enqueue() time because drops (kfree_skb()) are done while qdisc lock is held, delaying a dequeue() draining the queue. Nominal throughput can be reduced by 50 % when this happens, at a time we would like the dequeue() to proceed as fast as possible. Even FQ is vulnerable to this problem, while one of FQ goals was to provide some flow isolation. This patch adds a 'struct sk_buff **to_free' parameter to all qdisc->enqueue(), and in qdisc_drop() helper. I measured a performance increase of up to 12 %, but this patch is a prereq so that future batches in enqueue() can fly. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-15net_sched: sch_pie: defer skb freeingEric Dumazet
pie_change() can use rtnl_qdisc_drop() to benefit from deferred freeing. pie_reset() is already using qdisc_reset_queue() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-29net_sched: update hierarchical backlog tooWANG Cong
When the bottom qdisc decides to, for example, drop some packet, it calls qdisc_tree_decrease_qlen() to update the queue length for all its ancestors, we need to update the backlog too to keep the stats on root qdisc accurate. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-29sch_pie: schedule the timer after all init succeedWANG Cong
Cc: Vijay Subramanian <vijaynsu@cisco.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com>
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>
2014-02-13net: sched: Cleanup PIE commentsVijay Subramanian
Fix incorrect comment reported by Norbert Kiesel. Edit another comment to add more details. Also add references to algorithm (IETF draft and paper) to top of file. Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com> CC: Mythili Prabhu <mysuryan@cisco.com> CC: Norbert Kiesel <nkiesel@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-14net: replace macros net_random and net_srandom with direct calls to prandomAruna-Hewapathirane
This patch removes the net_random and net_srandom macros and replaces them with direct calls to the prandom ones. As new commits only seem to use prandom_u32 there is no use to keep them around. This change makes it easier to grep for users of prandom_u32. Signed-off-by: Aruna-Hewapathirane <aruna.hewapathirane@gmail.com> Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-06net: pkt_sched: PIE AQM schemeVijay Subramanian
Proportional Integral controller Enhanced (PIE) is a scheduler to address the bufferbloat problem. >From the IETF draft below: " Bufferbloat is a phenomenon where excess buffers in the network cause high latency and jitter. As more and more interactive applications (e.g. voice over IP, real time video streaming and financial transactions) run in the Internet, high latency and jitter degrade application performance. There is a pressing need to design intelligent queue management schemes that can control latency and jitter; and hence provide desirable quality of service to users. We present here a lightweight design, PIE(Proportional Integral controller Enhanced) that can effectively control the average queueing latency to a target value. Simulation results, theoretical analysis and Linux testbed results have shown that PIE can ensure low latency and achieve high link utilization under various congestion situations. The design does not require per-packet timestamp, so it incurs very small overhead and is simple enough to implement in both hardware and software. " Many thanks to Dave Taht for extensive feedback, reviews, testing and suggestions. Thanks also to Stephen Hemminger and Eric Dumazet for reviews and suggestions. Naeem Khademi and Dave Taht independently contributed to ECN support. For more information, please see technical paper about PIE in the IEEE Conference on High Performance Switching and Routing 2013. A copy of the paper can be found at ftp://ftpeng.cisco.com/pie/. Please also refer to the IETF draft submission at http://tools.ietf.org/html/draft-pan-tsvwg-pie-00 All relevant code, documents and test scripts and results can be found at ftp://ftpeng.cisco.com/pie/. For problems with the iproute2/tc or Linux kernel code, please contact Vijay Subramanian (vijaynsu@cisco.com or subramanian.vijay@gmail.com) Mythili Prabhu (mysuryan@cisco.com) Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com> Signed-off-by: Mythili Prabhu <mysuryan@cisco.com> CC: Dave Taht <dave.taht@bufferbloat.net> Signed-off-by: David S. Miller <davem@davemloft.net>