tcp: new TCP_INFO stats for RTO events
From: | Aananth V <aananthv-AT-google.com> | |
To: | Eric Dumazet <edumazet-AT-google.com> | |
Subject: | [PATCH net-next v2 0/2] tcp: new TCP_INFO stats for RTO events | |
Date: | Thu, 14 Sep 2023 14:36:19 +0000 | |
Message-ID: | <20230914143621.3858667-1-aananthv@google.com> | |
Cc: | netdev-AT-vger.kernel.org, Paolo Abeni <pabeni-AT-redhat.com>, David Miller <davem-AT-davemloft.net>, Jakub Kicinski <kuba-AT-kernel.org>, Neal Cardwell <ncardwell-AT-google.com>, Yuchung Cheng <ycheng-AT-google.com>, Aananth V <aananthv-AT-google.com> | |
Archive-link: | Article |
The 2023 SIGCOMM paper "Improving Network Availability with Protective ReRoute" has indicated Linux TCP's RTO-triggered txhash rehashing can effectively reduce application disruption during outages. To better measure the efficacy of this feature, this patch set adds three more detailed stats during RTO recovery and exports via TCP_INFO. Applications and monitoring systems can leverage this data to measure the network path diversity and end-to-end repair latency during network outages to improve their network infrastructure. Patch 1 fixes a bug in TFO SYNACK that we encountered while testing these new metrics. Patch 2 adds the new metrics to tcp_sock and tcp_info. v2: Addressed feedback from a check bot in patch 2 by removing the inline keyword from the tcp_update_rto_time and tcp_update_rto_stats functions. Changed a comment in include/net/tcp.h to fit under 80 words. Aananth V (2): tcp: call tcp_try_undo_recovery when an RTOd TFO SYNACK is ACKed tcp: new TCP_INFO stats for RTO events include/linux/tcp.h | 8 ++++++++ include/uapi/linux/tcp.h | 12 ++++++++++++ net/ipv4/tcp.c | 9 +++++++++ net/ipv4/tcp_input.c | 24 ++++++++++++++++++++---- net/ipv4/tcp_minisocks.c | 4 ++++ net/ipv4/tcp_timer.c | 17 +++++++++++++++-- 6 files changed, 68 insertions(+), 6 deletions(-) -- 2.42.0.283.g2d96d420d3-goog