Neal Cardwell via Bloat <[email protected]> writes: > On Tue, Nov 22, 2022 at 2:43 PM 'Bob McMahon' via BBR Development < > [email protected]> wrote: > >> Thanks for sharing this. Curious about how the xTSQ value can be set? Can >> it be done with sysctl? >> >> *We continue our analysis by using the ms-version of TSQ patch, which >> enables the tune of the TSQ size allowing each TCP variant to enqueue more >> than 1 ms of data at the current TCP rate. In particular, we allow to >> enqueue the equivalent of x ms of data, naming each test xTSQ, with x being >> an integer value. It is important to notice that this patch has been >> included in the Linux kernel mainline, and each Wi-Fi driver can now set >> the desired xTSQ value**.* >> > > I believe they are setting the xTSQ value using the sk_pacing_shift field, > which was added here: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3a9b76fd0db9f0d426533f96a68a62a58753a51e > > AFAIK the intent is only for drivers to set that, and there's no sysctl for > that, but of course you could add a sysctl for testing if you wanted. > :-)
Yup, indeed this is what mac80211 fiddles with: https://elixir.bootlin.com/linux/latest/source/net/mac80211/main.c#L739 https://elixir.bootlin.com/linux/latest/source/net/mac80211/tx.c#L4156 AFAICT, no in-tree drivers override the value set by mac80211. I believe the tests in that paper were conducted with this series applied: https://lore.kernel.org/all/[email protected]/ -Toke _______________________________________________ Bloat mailing list [email protected] https://lists.bufferbloat.net/listinfo/bloat
