kernel/net/sched/sch_plug.c, branch linux-5.1.y

net: sched: sch: add extack for change qdisc ops

2017-12-21T17:32:50Z

This patch adds extack support for change callback for qdisc ops structtur to prepare per-qdisc specific changes for extack. Cc: David Ahern Acked-by: Jamal Hadi Salim Signed-off-by: Alexander Aring Signed-off-by: David S. Miller

net: sched: sch: add extack for init callback

2017-12-21T17:32:50Z

This patch adds extack support for init callback to prepare per-qdisc specific changes for extack. Cc: David Ahern Acked-by: Jamal Hadi Salim Signed-off-by: Alexander Aring Signed-off-by: David S. Miller

net_sched: drop packets after root qdisc lock is released

2016-06-25T16:19:35Z

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 Acked-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller

net_sched: sch_plug: use a private throttled status

2016-06-11T06:58:20Z

We want to get rid of generic qdisc throttled management, so this qdisc has to use a private flag. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

sched: remove qdisc_rehape_fail

2016-06-09T06:58:51Z

After the removal of TCA_CBQ_POLICE in cbq scheduler qdisc->reshape_fail is always NULL, i.e. qdisc_rehape_fail is now the same as qdisc_drop. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller

net: sched: drop all special handling of tx_queue_len == 0

2015-08-18T18:55:08Z

Those were all workarounds for the formerly double meaning of tx_queue_len, which broke scheduling algorithms if untreated. Now that all in-tree drivers have been converted away from setting tx_queue_len = 0, it should be safe to drop these workarounds for categorically broken setups. Signed-off-by: Phil Sutter Cc: Jamal Hadi Salim Signed-off-by: David S. Miller

sch_plug: purge buffered packets during reset

2015-07-25T05:57:14Z

Otherwise the skbuff related structures are not correctly refcount'ed. Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Signed-off-by: David S. Miller

net_sched: sch_plug: plug_qdisc_ops is static

2012-02-13T21:04:40Z

net/sched/sch_plug.c:211:18: warning: symbol 'plug_qdisc_ops' was not declared. Should it be static? Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net/sched: sch_plug - Queue traffic until an explicit release command

2012-02-07T17:54:56Z

The qdisc supports two operations - plug and unplug. When the qdisc receives a plug command via netlink request, packets arriving henceforth are buffered until a corresponding unplug command is received. Depending on the type of unplug command, the queue can be unplugged indefinitely or selectively. This qdisc can be used to implement output buffering, an essential functionality required for consistent recovery in checkpoint based fault-tolerance systems. Output buffering enables speculative execution by allowing generated network traffic to be rolled back. It is used to provide network protection for Xen Guests in the Remus high availability project, available as part of Xen. This module is generic enough to be used by any other system that wishes to add speculative execution and output buffering to its applications. This module was originally available in the linux 2.6.32 PV-OPS tree, used as dom0 for Xen. For more information, please refer to http://nss.cs.ubc.ca/remus/ and http://wiki.xensource.com/xenwiki/Remus Changes in V3: * Removed debug output (printk) on queue overflow * Added TCQ_PLUG_RELEASE_INDEFINITE - that allows the user to use this qdisc, for simple plug/unplug operations. * Use of packet counts instead of pointers to keep track of the buffers in the queue. Signed-off-by: Shriram Rajagopalan Signed-off-by: Brendan Cully [author of the code in the linux 2.6.32 pvops tree] Signed-off-by: David S. Miller