tcp: remove tcptw, the compressed timewait state structure
ClosedPublic
Actions

Authored by glebius on Aug 31 2022, 5:11 AM.

Details

Reviewers

tuexen

Group Reviewers

transport

Commits

rG0d7445193abc: tcp: remove tcptw, the compressed timewait state structure

Summary

The memory savings the tcptw brought back in 2003 no longer justify the
complexity required to maintain it. For longer explanation please check
out this email:

https://lists.freebsd.org/archives/freebsd-net/2022-January/001206.html

This change just removes tcptw and leaves INP_TIMEWAIT. The flag will
be removed in step 2. This makes it easier to review and possibly debug
the changes.

Diff Detail

Repository

rG FreeBSD src repository

Lint

Lint Skipped

Unit

Tests Skipped

Build Status

Buildable 47192
Build 44079: arc lint + arc unit

Event Timeline

glebius created this revision.Aug 31 2022, 5:11 AM

Herald added 1 blocking reviewer(s): transport. · View Herald TranscriptAug 31 2022, 5:11 AM

Herald added subscribers: melifaro, ae, imp. · View Herald Transcript

glebius requested review of this revision.Aug 31 2022, 5:11 AM

glebius added a parent revision: D36397: tcp_timers: provide tcp_timer_drop() and tcp_timer_close().

Harbormaster completed remote builds in B47192: Diff 110004.Aug 31 2022, 5:11 AM

glebius added a child revision: D36399: tcp: in tcp_usr_detach() remove special handling of compressed time-wait.Aug 31 2022, 5:11 AM

Reading your summary, the reader is left with "and what do you do instead?" Would probably be good (here and in step 2) to explain somewhere what the expected path forward is as I am not assuming you are removing timewait functionality from TCP entirely?

In D36398#826783, @bz wrote:

Reading your summary, the reader is left with "and what do you do instead?" Would probably be good (here and in step 2) to explain somewhere what the expected path forward is as I am not assuming you are removing timewait functionality from TCP entirely?

Will improve commit message on next rebase or fixup of the patch.

glebius retitled this revision from tcp: remove compressed timewait state structure, step 1 to tcp: remove tcptw, the compressed timewait state structure.Oct 5 2022, 4:45 PM