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.
Boqun Feng
authored
`SpinLock`'s backend can be used for `SpinLockIrq`, if the interrupts
are disabled. And it actually provides performance gains since
interrupts are not needed to be disabled anymore. So add
`Backend::BackendInContext` to describe the case where one backend can
be used for another. Use the it to implement the `lock_with()` so that
`SpinLockIrq` can avoid disabling interrupts by using `SpinLock`'s
backend.
Signed-off-by: 
Boqun Feng <boqun.feng@gmail.com>