Tcp rto rfc 6298 compliant #7
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We want to get rid of generic qdisc throttled management, so this qdisc has to use a private flag. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
So far no qdisc ever unset the throttled bit at enqueue() time, so CBQ usage of qdisc_is_throttled() was flaky. Since __QDISC_STATE_THROTTLED set/unset is way too expensive considering that only CBQ was eventually caring for this status, it would make sense to implement a Qdisc ops ->is_throttled() if we find that this is needed. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Looks like it is only there as some optimization attempt. Since __QDISC_STATE_THROTTLED set/unset is way too expensive, and netem is the last user, just remove this check. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
__QDISC_STATE_THROTTLED bit manipulation is rather expensive for HTB and few others. I already removed it for sch_fq in commit f2600cf ("net: sched: avoid costly atomic operation in fq_dequeue()") and so far nobody complained. When one ore more packets are stuck in one or more throttled HTB class, a htb dequeue() performs two atomic operations to clear/set __QDISC_STATE_THROTTLED bit, while root qdisc lock is held. Removing this pair of atomic operations bring me a 8 % performance increase on 200 TCP_RR tests, in presence of throttled classes. This patch has no side effect, since nothing actually uses disc_is_throttled() anymore. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
In IPv6 the ToS values are part of the flowlabel in flowi6 and get extracted during fib rule lookup, but we forgot to correctly initialize the flowlabel before the routing lookup. Reported-by: <liam.mcbirnie@boeing.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Since msleep is based on jiffies the PHY reset could take longer than expected. So use msleep for values greater than 20 msec otherwise usleep_range. Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Acked-by: Fugang Duan <fugang.duan@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
sch_atm returns this when TC_ACT_SHOT classification occurs. But all other schedulers that use tc_classify (htb, hfsc, drr, fq_codel ...) return NET_XMIT_SUCCESS | __BYPASS in this case so just do that in atm. BATMAN uses it as an intermediate return value to signal forwarding vs. buffering, but it did not return POLICED to callers outside of BATMAN. Reviewed-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
The commit e858fae ("virtio_net: use common code for virtio_net_hdr and skb GSO conversion") replaced the tun code for header manipulation with the generic helpers. While doing so, it implictly moved the skb_partial_csum_set() invocation after eth_type_trans(), which invalidate the current gso start/offset values. Fix it by moving the helper invocation before the mac pulling. Fixes: e858fae ("virtio_net: use common code for virtio_net_hdr and skb GSO conversion") Reported-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adjusts Linux RTO calculation to be RFC6298 Standard compliant with two exceptions: - Instead of using a MinRTO of 1 second use Linux MinRTO -> RTO is not rounded up to MinRTO if it is less anyways - RTTVAR flooring: RTTVAR = max(RTTVAR, MinRTO) -> >= MinRTO will always be added to computed RTO The first version of this patch was without RTTVAR flooring. However, this seems to be too aggressive and cause too many (spurious) retransmissions. This version now uses RTTVAR flooring and seems to be advantageous compared to Linux historic RTO computation. As disadvantage of RTTVAR flooring sender limited flows no longer benefit from decreased response time on packet loss. A side effect of using this implementation is tcp_sock struct variables u32 mdev_max_us and u32 mdev_us become obsolete and consequently are being removed. Analysis of first patch version compared to Linux implementation: https://docs.google.com/document/d/1pKmPfnQb6fDK4qpiNVkN8cQyGE4wYDZukcuZfR-BnnM/ Reasoning for historic design: Sarolahti, P.; Kuznetsov, A. (2002). Congestion Control in Linux TCP. Conference Paper. Proceedings of the FREENIX Track. 2002 USENIX Annual https://www.cs.helsinki.fi/research/iwtcp/papers/linuxtcp.pdf Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: Daniel Metz <dmetz@mytum.de> Cc: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com>
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