Dear Michael: Thank you for digging deeply into packet pacing, TSQ, etc. I think there are some interesting new possibilities in probing (especially during slow start) that could make the core idea even more effective than it is. I also tend to think that attempting it in various cloudy environments and virtualization schemes, and with certain drivers, the side effects are not as well understood as I would like. For example, AWS's nitro lacks BQL as does virtio-net.
I think the netdev community, now cc'd, would be interested in your document and explorations so far, below. I hope for more enlightenment. On Wed, Feb 7, 2024 at 6:57 AM Michael Welzl via Bloat <[email protected]> wrote: > > Dear de-bloaters of buffers, > Esteemed experts of low delay and pacing! > > I have no longer been satisfied with high-level descriptions of how pacing > works in Linux, and how it interacts with TSQ (I’ve seen some, in various > papers, over the years) - but I wanted to REALLY understand it. So, I have > dug through the code. > > I documented this experience here: > https://docs.google.com/document/d/1-uXnPDcVBKmg5krkG5wYBgaA2yLSFK_kZa7xGDWc7XU/edit?usp=sharing > but it has some holes and may have mistakes. > > Actually, my main problem is that I don’t really know what goes on when I > configure a larger IW… things seem to get quite “off” there. Why? Anyone up > for solving that riddle? ;-) > (see the tests I documented towards the end of the document) > > Generally, if someone who has their hands on files such as tcp_output.c all > the time could take a look, and perhaps “fill” my holes, or improve anything > that might be wrong, that would be fantastic! I think that anyone should be > allowed to comment and make suggestions in this doc. > > MANY thanks to whoever finds the time to take a look ! > > Cheers, > Michael > > _______________________________________________ > Bloat mailing list > [email protected] > https://lists.bufferbloat.net/listinfo/bloat -- 40 years of net history, a couple songs: https://www.youtube.com/watch?v=D9RGX6QFm5E Dave Täht CSO, LibreQos _______________________________________________ Bloat mailing list [email protected] https://lists.bufferbloat.net/listinfo/bloat
