b8b58b3280
Currently kernel has scattered tagged pointer usages hacked by hand in plain code, without a unique and portable functionset to highlight the tagged pointer itself and wrap these hacked code in order to clean up all over meaningless magic masks. Therefore, this patch introduces simple generic methods to fold tags into a pointer integer. It currently supports the last n bits of the pointer for tags, which can be selected by users. In addition, it will also be used for the upcoming EROFS filesystem, which heavily uses tagged pointer approach for high performance and reducing extra memory allocation. Link: https://en.wikipedia.org/wiki/Tagged_pointer Signed-off-by: Gao Xiang <gaoxiang25@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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.