Pete Heist <[email protected]> writes: >>> On Nov 15, 2017, at 9:04 PM, Dave Taht <[email protected]> wrote: >>> >>> >>> Dave Taht <[email protected]> writes: >>> >>> TCP RTT ~= 8ms with default qdisc, throughput ~= 940 Mbit >>> TCP RTT ~= 4.5ms with ‘cake unlimited’, throughput ~= 920 Mbit >>> TCP RTT ~= 1ms with ‘cake unlimited lan’, throughput ~= 920 Mbit >>> >>> >>> This was with BQL in play? Monitoring BQL's behavior might help. >>> >>> I'd also love to know an exact setting for the shaper as a close as >>> possible to the underlying bandwidth of ethernet. However, I tend to be >>> plagued with >>> >>> >>> Yes, with BQL (Intel I210 with igb driver on the APU2). An rrul_be test >>> with — >>> socket-stats. >> >> https://github.com/ffainelli/bqlmon was a tool for looking at bql more >> directly. >> >> I had forked it for some reason or another: >> >> https://github.com/dtaht/bqlmon > > Nice, that does work for me. It’s interesting that there are four queues for > the > igb driver, 00 - 03, and when I try an rrul_be_nflows test, not all four > queues > are necessarily used. Once I get >= 8 flows in each direction they usually are > though. I suppose this is the driver deciding when to start using another > queue > or not.
Usually it is selected via a hash. In more than a few cases, however, the designer of the hardware intended it as a strict priority queue. In other cases, it's based on the CPU. In all cases such a limited number of queues tends to cause oddities. I think it was the mvneta (?) that had the strict priority queue idea baked into it, which we ended up disabling entirely and going with just one hardware queue. > > Cake does seem to visibly reduce the size of the queues. I generally observe that TSO/GRO/etc tends to make BQL's queues 3-5 times larger than they are without those offloads - no way to fix it, short of doing what cake does to peel those apart. > For whatever > terminal/ncurses weirdness reason though, the bar graphs may be sometimes > blowing off the top of my 45 row screen, but it doesn’t entirely ruin the > experience. Maybe that was why I forked it? _______________________________________________ Cake mailing list [email protected] https://lists.bufferbloat.net/listinfo/cake
