80d55154b2
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. 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. Signed-off-by: Felix Fietkau <nbd@nbd.name> Link: https://lore.kernel.org/r/20210127055735.78599-4-nbd@nbd.name Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.