mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-04-29 17:35:36 -04:00
cee7a36ecb
This variant is similar to the AVX2 version, but benefits from the AVX-512 rotate instructions and the additional registers, so it can operate without any data on the stack. It uses ymm registers only to avoid the massive core throttling on Skylake-X platforms. Nontheless does it bring a ~30% speed improvement compared to the AVX2 variant for random encryption lengths. The AVX2 version uses "rep movsb" for partial block XORing via the stack. With AVX-512, the new "vmovdqu8" can do this much more efficiently. The associated "kmov" instructions to work with dynamic masks is not part of the AVX-512VL instruction set, hence we depend on AVX-512BW as well. Given that the major AVX-512VL architectures provide AVX-512BW and this extension does not affect core clocking, this seems to be no problem at least for now. Signed-off-by: Martin Willi <martin@strongswan.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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.