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.
Frederic Weisbecker
authored
The barrier_mutex is used currently to protect (de-)offloading operations and prevent from nocb_lock locking imbalance in rcu_barrier() and shrinker, and also from misordered RCU barrier invocation. Now since RCU (de-)offloading is going to happen on offline CPUs, an RCU barrier will have to be executed while transitionning from offloaded to de-offloaded state. And this can't happen while holding the barrier_mutex. Introduce a NOCB mutex to protect (de-)offloading transitions. The barrier_mutex is still held for now when necessary to avoid barrier callbacks reordering and nocb_lock imbalance. Signed-off-by:Frederic Weisbecker <frederic@kernel.org> Signed-off-by:
Paul E. McKenney <paulmck@kernel.org> Reviewed-by:
Neeraj Upadhyay <neeraj.upadhyay@kernel.org>