385b599e8c
When running in an interrupt handler, raise_softirq() and raise_softirq_irqoff() have extremely low overhead: They simply set a bit in a per-CPU mask, which is checked upon exit from that interrupt handler. Therefore, if rcu_read_unlock_special() is invoked within an interrupt handler and RCU_SOFTIRQ is in use, this commit make use of raise_softirq_irqoff() even if there is no expedited grace period in flight and even if this is not a nohz_full CPU. Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.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.