kernel/linux.git/net/ipv4/tcp_lp.c, branch linux-7.1.y

net: tcp_lp: fix kernel-doc warnings and update outdated reference links

2025-10-29T00:52:44+00:00

Fix kernel-doc warnings in tcp_lp.c by adding missing parameter descriptions for tcp_lp_cong_avoid() and tcp_lp_pkts_acked() when building with W=1. Also replace invalid URLs in the file header comment with the currently valid links to the TCP-LP paper and implementation page. No functional changes. Signed-off-by: Rakuram Eswaran Reviewed-by: Simon Horman Link: https://patch.msgid.link/20251025-net_ipv4_tcp_lp_c-v1-1-058cc221499e@gmail.com Signed-off-by: Jakub Kicinski

tcp: rename tcp_time_stamp() to tcp_time_stamp_ts()

2023-10-23T08:35:01+00:00

This helper returns a TSval from a TCP socket. It currently calls tcp_time_stamp_ms() but will soon be able to return a usec based TSval, depending on an upcoming tp->tcp_usec_ts field. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp: add accessors to read/set tp->snd_cwnd

2022-04-06T19:05:41+00:00

We had various bugs over the years with code breaking the assumption that tp->snd_cwnd is greater than zero. Lately, syzbot reported the WARN_ON_ONCE(!tp->prior_cwnd) added in commit 8b8a321ff72c ("tcp: fix zero cwnd in tcp_cwnd_reduction") can trigger, and without a repro we would have to spend considerable time finding the bug. Instead of complaining too late, we want to catch where and when tp->snd_cwnd is set to an illegal value. Signed-off-by: Eric Dumazet Suggested-by: Yuchung Cheng Cc: Neal Cardwell Acked-by: Yuchung Cheng Link: https://lore.kernel.org/r/20220405233538.947344-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski

ipv4: tcp_lp.c: Couple of typo fixes

2021-03-29T00:31:13+00:00

s/resrved/reserved/ s/within/within/ Signed-off-by: Bhaskar Chowdhury Signed-off-by: David S. Miller

net: ipv4: Fix some kerneldoc warnings in TCP Low Priority

2020-10-30T19:10:57+00:00

net//ipv4/tcp_lp.c:120: warning: Function parameter or member 'sk' not described in 'tcp_lp_cong_avoid' net//ipv4/tcp_lp.c:135: warning: Function parameter or member 'sk' not described in 'tcp_lp_remote_hz_estimator' net//ipv4/tcp_lp.c:188: warning: Function parameter or member 'sk' not described in 'tcp_lp_owd_calculator' net//ipv4/tcp_lp.c:222: warning: Function parameter or member 'rtt' not described in 'tcp_lp_rtt_sample' net//ipv4/tcp_lp.c:222: warning: Function parameter or member 'sk' not described in 'tcp_lp_rtt_sample' net//ipv4/tcp_lp.c:265: warning: Function parameter or member 'sk' not described in 'tcp_lp_pkts_acked' net//ipv4/tcp_lp.c:97: warning: Function parameter or member 'sk' not described in 'tcp_lp_init' There are still a few kerneldoc warnings after this fix. Signed-off-by: Andrew Lunn Link: https://lore.kernel.org/r/20201028012703.931632-1-andrew@lunn.ch Signed-off-by: Jakub Kicinski

treewide: Add SPDX license identifier for more missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

tcp: switch TCP TS option (RFC 7323) to 1ms clock

2017-05-17T20:06:01+00:00

TCP Timestamps option is defined in RFC 7323 Traditionally on linux, it has been tied to the internal 'jiffies' variable, because it had been a cheap and good enough generator. For TCP flows on the Internet, 1 ms resolution would be much better than 4ms or 10ms (HZ=250 or HZ=100 respectively) For TCP flows in the DC, Google has used usec resolution for more than two years with great success [1] Receive size autotuning (DRS) is indeed more precise and converges faster to optimal window size. This patch converts tp->tcp_mstamp to a plain u64 value storing a 1 usec TCP clock. This choice will allow us to upstream the 1 usec TS option as discussed in IETF 97. [1] https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-tcp-options-for-low-latency-00.pdf Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller

tcp_lp: cache tcp_time_stamp

2017-05-17T20:06:01+00:00

tcp_time_stamp will become slightly more expensive soon, cache its value. Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller

tcp: fix wraparound issue in tcp_lp

2017-05-02T19:07:02+00:00

Be careful when comparing tcp_time_stamp to some u32 quantity, otherwise result can be surprising. Fixes: 7c106d7e782b ("[TCP]: TCP Low Priority congestion control") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp: make undo_cwnd mandatory for congestion modules

2016-11-21T18:20:17+00:00

The undo_cwnd fallback in the stack doubles cwnd based on ssthresh, which un-does reno halving behaviour. It seems more appropriate to let congctl algorithms pair .ssthresh and .undo_cwnd properly. Add a 'tcp_reno_undo_cwnd' function and wire it up for all congestion algorithms that used to rely on the fallback. Cc: Eric Dumazet Cc: Yuchung Cheng Cc: Neal Cardwell Signed-off-by: Florian Westphal Signed-off-by: David S. Miller