mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-09-22 09:34:56 +02:00
Andreas Gruenbacher
f27614652c
The eytzinger code was previously relying on the following wrap-around properties and their "eytzinger0" equivalents: eytzinger1_prev(0, size) == eytzinger1_last(size) eytzinger1_next(0, size) == eytzinger1_first(size) However, these properties are no longer relied upon and no longer necessary, so remove the corresponding asserts and forbid the use of eytzinger1_prev(0, size) and eytzinger1_next(0, size). This allows to further simplify the code in eytzinger1_next() and eytzinger1_prev(): where the left shifting happens, eytzinger1_next() is trying to move i to the lowest child on the left, which is equivalent to doubling i until the next doubling would cause it to be greater than size. This is implemented by shifting i to the left so that the most significant bits align and then shifting i to the right by one if the result is greater than size. Likewise, eytzinger1_prev() is trying to move to the lowest child on the right; the same applies here. The 1-offset in (size - 1) in eytzinger1_next() isn't needed at all, but the equivalent offset in eytzinger1_prev() is surprisingly needed to preserve the 'eytzinger1_prev(0, size) == eytzinger1_last(size)' property. However, since we no longer support that property, we can get rid of these offsets as well. This saves one addition in each function and makes the code less confusing. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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 reStructuredText 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.