Felix Fietkau <nbd@xxxxxxxx> writes: > The biggest flaw in current minstrel_ht is the fact that it needs way too > many probing packets to be able to quickly find the best rate. > Depending on the wifi hardware and operating mode, this can significantly > reduce throughput when not operating at the highest available data rate. > > In order to be able to significantly reduce the amount of rate sampling, > we need a much smarter selection of probing rates. > > The new approach introduced by this patch maintains a limited set of > available rates to be tested during a statistics window. > > They are split into distinct categories: > - MINSTREL_SAMPLE_TYPE_INC - incremental rate upgrade: > Pick the next rate group and find the first rate that is faster than > the current max. throughput rate > - MINSTREL_SAMPLE_TYPE_JUMP - random testing of higher rates: > Pick a random rate from the next group that is faster than the current > max throughput rate. This allows faster adaptation when the link changes > significantly > - MINSTREL_SAMPLE_TYPE_SLOW - test a rate between max_prob, max_tp2 and > max_tp in order to reduce the gap between them > > In order to prioritize sampling, every 6 attempts are split into 3x INC, > 2x JUMP, 1x SLOW. > > Available rates are checked and refilled on every stats window update. Very cool! > With this approach, we finally get a very small delta in throughput when > comparing setting the optimal data rate as a fixed rate vs normal rate > control operation. Can you quantify this "very small delta"? Would love to see some benchmark data :) -Toke
