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29f834aa32
Before Google adopted FQ for its production servers, we had to ensure AF4 packets would get a higher share than BE1 ones. As discussed this week in Netconf 2023 in Paris, it is time to upstream this for public use. After this patch FQ can replace pfifo_fast, with the following differences : - FQ uses WRR instead of strict prio, to avoid starvation of low priority packets. - We make sure each band/prio tracks its own usage against sch->limit. This was done to make sure flood of low priority packets would not prevent AF4 packets to be queued. Contributed by Willem. - priomap can be changed, if needed (default value are the ones coming from pfifo_fast). In this patch, we set default band weights so that : - high prio (band=0) packets get 90% of the bandwidth if they compete with low prio (band=2) packets. - high prio packets get 75% of the bandwidth if they compete with medium prio (band=1) packets. Following patch in this series adds the possibility to tune the per-band weights. As we added many fields in 'struct fq_sched_data', we had to make sure to have the first cache line read-mostly, and avoid wasting precious cache lines. More optimizations are possible but will be sent separately. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Dave Taht <dave.taht@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.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.