BMC/Intel-BMC/linux.git/net/sched/sch_fq.c, branch dev

pkt_sched: fq: correct spelling of locally

2015-04-02T02:52:29+00:00

Correct spelling of locally. Also remove extra space before tab character in struct fq_flow. Signed-off-by: Simon Horman Signed-off-by: David S. Miller

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

2015-02-05T22:33:28+00:00

Conflicts: drivers/net/vxlan.c drivers/vhost/net.c include/linux/if_vlan.h net/core/dev.c The net/core/dev.c conflict was the overlap of one commit marking an existing function static whilst another was adding a new function. In the include/linux/if_vlan.h case, the type used for a local variable was changed in 'net', whereas the function got rewritten to fix a stacked vlan bug in 'net-next'. In drivers/vhost/net.c, Al Viro's iov_iter conversions in 'net-next' overlapped with an endainness fix for VHOST 1.0 in 'net'. In drivers/net/vxlan.c, vxlan_find_vni() added a 'flags' parameter in 'net-next' whereas in 'net' there was a bug fix to pass in the correct network namespace pointer in calls to this function. Signed-off-by: David S. Miller

pkt_sched: fq: better control of DDOS traffic

2015-02-05T06:15:45+00:00

FQ has a fast path for skb attached to a socket, as it does not have to compute a flow hash. But for other packets, FQ being non stochastic means that hosts exposed to random Internet traffic can allocate million of flows structure (104 bytes each) pretty easily. Not only host can OOM, but lookup in RB trees can take too much cpu and memory resources. This patch adds a new attribute, orphan_mask, that is adding possibility of having a stochastic hash for orphaned skb. Its default value is 1024 slots, to mimic SFQ behavior. Note: This does not apply to locally generated TCP traffic, and no locally generated traffic will share a flow structure with another perfect or stochastic flow. This patch also handles the specific case of SYNACK messages: They are attached to the listener socket, and therefore all map to a single hash bucket. If listener have set SO_MAX_PACING_RATE, hoping to have new accepted socket inherit this rate, SYNACK might be paced and even dropped. This is very similar to an internal patch Google have used more than one year. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp: do not pace pure ack packets

2015-02-05T04:36:31+00:00

When we added pacing to TCP, we decided to let sch_fq take care of actual pacing. All TCP had to do was to compute sk->pacing_rate using simple formula: sk->pacing_rate = 2 * cwnd * mss / rtt It works well for senders (bulk flows), but not very well for receivers or even RPC : cwnd on the receiver can be less than 10, rtt can be around 100ms, so we can end up pacing ACK packets, slowing down the sender. Really, only the sender should pace, according to its own logic. Instead of adding a new bit in skb, or call yet another flow dissection, we tweak skb->truesize to a small value (2), and we instruct sch_fq to use new helper and not pace pure ack. Note this also helps TCP small queue, as ack packets present in qdisc/NIC do not prevent sending a data packet (RPC workload) This helps to reduce tx completion overhead, ack packets can use regular sock_wfree() instead of tcp_wfree() which is a bit more expensive. This has no impact in the case packets are sent to loopback interface, as we do not coalesce ack packets (were we would detect skb->truesize lie) In case netem (with a delay) is used, skb_orphan_partial() also sets skb->truesize to 1. This patch is a combination of two patches we used for about one year at Google. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

pkt_sched: fq: avoid hang when quantum 0

2015-02-05T04:07:39+00:00

Configuring fq with quantum 0 hangs the system, presumably because of a non-interruptible infinite loop. Either way quantum 0 does not make sense. Reproduce with: sudo tc qdisc add dev lo root fq quantum 0 initial_quantum 0 ping 127.0.0.1 Signed-off-by: Kenneth Klette Jonassen Acked-by: Eric Dumazet Signed-off-by: David S. Miller

pkt_sched: fq: remove useless TIME_WAIT check

2015-01-29T07:23:57+00:00

TIME_WAIT sockets are not owning any skb. ip_send_unicast_reply() and tcp_v6_send_response() both use regular sockets. We can safely remove a test in sch_fq and save one cache line miss, as sk_state is far away from sk_pacing_rate. Tested at Google for about one year. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

pkt_sched: fq: increase max delay from 125 ms to one second

2014-11-26T17:08:04+00:00

FQ/pacing has a clamp of delay of 125 ms, to avoid some possible harm. It turns out this delay is too small to allow pacing low rates : Some ISP setup very aggressive policers as low as 16kbit. Now TCP stack has spurious rtx prevention, it seems safe to increase this fixed parameter, without adding a qdisc attribute. Signed-off-by: Eric Dumazet Cc: Yang Yingliang Signed-off-by: David S. Miller

net: sched: avoid costly atomic operation in fq_dequeue()

2014-10-06T04:55:10+00:00

Standard qdisc API to setup a timer implies an atomic operation on every packet dequeue : qdisc_unthrottled() It turns out this is not really needed for FQ, as FQ has no concept of global qdisc throttling, being a qdisc handling many different flows, some of them can be throttled, while others are not. Fix is straightforward : add a 'bool throttle' to qdisc_watchdog_schedule_ns(), and remove calls to qdisc_unthrottled() in sch_fq. Signed-off-by: Eric Dumazet 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: use ktime_get_ns() and ktime_get_real_ns() helpers

2014-08-23T02:57:23+00:00

ktime_get_ns() replaces ktime_to_ns(ktime_get()) ktime_get_real_ns() replaces ktime_to_ns(ktime_get_real()) Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller