[tcpm] A description of Linux pacing

[Michael Welzl <[e-mail]>]

Dear TCPM and ICCRG (I assume that there’s so much overlap with people in CCWG that it would just be spamming to send it there too?),

Over the last two weeks or so, I have put some effort into trying to understand how Linux pacing *really* works  (I had some descriptions that were somewhat high-level; I wanted to obtain a more precise lower-level understanding).
I wrote a document, just for myself, explaining what goes on in the code, as I can’t even try to follow the Linux kernel without taking notes.

After a first iteration, I shared it with the bufferbloat mailing list, in the hope of getting corrections.
I did!  Most notably (but not only), Neal Cardwell helped me a ton - and now the document should be quite thorough and hopefully correct.

While I only did this for myself and just asked the list for help, several people have in the meantime told me that this document is actually valuable for the community - and so I thought I should share it here, too.
It lives as a Google doc at this URL:
https://docs.google.com/document/d/1-uXnPDcVBKmg5krkG5wYBgaA2yLSFK_kZa7xGDWc7XU/edit?usp=sharing <https://docs.google.com/document/d/1-uXnPDcVBKmg5krkG5wYBgaA2yLSFK_kZa7xGDWc7XU/edit?usp=sharing>

Comments or fixes are very welcome!
Please feel free to forward this as you want.

I know that Google docs is not the format that we people here normally use  :-)   well, if someone thinks that it would indeed be useful to write this up as an I-D (probably skipping all the code details though), please let me know - I can do that, and I can also present it if there’s interest (but in Vancouver, not Brisbane).

Cheers,
Michael