On Fri, 29 May 2026 09:13:44 +1000 Matthieu Baerts wrote: > Hi Jakub, > > On 29/05/2026 07:42, Jakub Kicinski wrote: > > On Wed, 27 May 2026 22:11:33 +1000 Matthieu Baerts (NGI0) wrote: > >> Bufferbloat is baaaad, even in our selftests: let's kill it (or at least > >> reduce it). By doing that, the tests (seem to) have a more stable > >> transfer, and are then less unstable. That's what patches 1-2 are doing, > >> and they can be backported up to 5.10. > > > > Could you explain a little more what this is actually fixing? > > The simult_flows.sh test simulates very low speed links using netem > qdiscs. With the current configuration, still a large amount of packets > can be queued, which means high TCP RTT samples and then large receive > buffer size. Minimal inaccuracy in the pacing rate can lead to using > only one subflow towards the end of the connection for a considerable > amount of data, while the test expects to use the 2 available paths in > parallel. > > > Does it give a huge increase in test stability? > I would say no: the test was not that flaky, mainly on NIPA in fact, and > around 4% in the last 100 tests [1]. On my side, I had to get my system > busy to reproduce the issues. My hope is that the success rate on NIPA > switches from 96 to ~100%. No failure since its introduction in > "net-next-2026-05-27--15-00". > > I sent them to net, just to increase the stability when validating > stable kernels as well. But all of this is not urgent, and this series > can be applied in net-next if preferred. Do you want me to resend this > series targeting net-next?
Thanks for explaining, I will take these via net-next, no problem.
