456cfbc65c
Add an rtlock_task pointer to rt_mutex_wake_q, which allows to handle the RT specific wakeup for spin/rwlock waiters. The pointer is just consuming 4/8 bytes on the stack so it is provided unconditionaly to avoid #ifdeffery all over the place. This cannot use a regular wake_q, because a task can have concurrent wakeups which would make it miss either lock or the regular wakeups, depending on what gets queued first, unless task struct gains a separate wake_q_node for this, which would be overkill, because there can only be a single task which gets woken up in the spin/rw_lock unlock path. No functional change for non-RT enabled kernels. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210815211303.253614678@linutronix.de
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.