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tcp: remove tcptw, the compressed timewait state structure
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Authored by glebius on Aug 31 2022, 5:11 AM.

Details

Reviewers
tuexen
Group Reviewers
transport
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 47707
Build 44594: arc lint + arc unit

Event Timeline

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

Rebase, improve commit message.

Update the commit message, attempt 2.

tuexen added a subscriber: tuexen.

Just a thought for a follow-up cleanup: possibly get rid of tcp_timewait.c and move the functions left to other places.

This revision is now accepted and ready to land.Oct 7 2022, 12:08 PM