1e67575a58
This is the first real user of the XDP_XMIT_FLUSH flag. As pointed out many times, XDP_REDIRECT without using BPF maps is significant slower than the map variant. This is primary due to the lack of bulking, as the ndo_xdp_flush operation is required after each frame (to avoid frames hanging on the egress device). It is still possible to optimize this case. Instead of invoking two NDO indirect calls, which are very expensive with CONFIG_RETPOLINE, instead instruct ndo_xdp_xmit to flush via XDP_XMIT_FLUSH flag. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.