696207d425
Non RT kernels need to protect FPU against preemption and bottom half processing. This is achieved by disabling bottom halves via local_bh_disable() which implictly disables preemption. On RT kernels this protection mechanism is not sufficient because local_bh_disable() does not disable preemption. It serializes bottom half related processing via a CPU local lock. As bottom halves are running always in thread context on RT kernels disabling preemption is the proper choice as it implicitly prevents bottom half processing. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20220505163207.85751-3-bigeasy@linutronix.de Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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.