This patch series is a bug fix for a TCP loss recovery performance bug reported independently in recent netdev threads: (i) July 26, 2017: netdev thread "TCP fast retransmit issues" (ii) July 26, 2017: netdev thread: "[PATCH V2 net-next] TLP: Don't reschedule PTO when there's one outstanding TLP retransmission"
Many thanks to Klavs Klavsen and Mao Wenan for the detailed reports, traces, and packetdrill test cases, which enabled us to root-cause this issue and verify the fix. Neal Cardwell (3): tcp: introduce tcp_rto_delta_us() helper for xmit timer fix tcp: enable xmit timer fix by having TLP use time when RTO should fire tcp: fix xmit timer to only be reset if data ACKed/SACKed include/net/tcp.h | 10 ++++++++++ net/ipv4/tcp_input.c | 30 +++++++++++++++++------------- net/ipv4/tcp_output.c | 21 ++++----------------- 3 files changed, 31 insertions(+), 30 deletions(-) -- 2.14.0.rc0.400.g1c36432dff-goog