mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-11 05:17:10 +09:00
7f36ef82e5
Currently, the code provides an extra wakeup for the no-CBs grace-period kthread if one of its CPUs is generating excessive numbers of callbacks. But satisfying though it is to wake something up when things are going south, unless the thing being awakened can actually help solve the problem, that extra wakeup does nothing but consume additional CPU time, which is exactly what you don't want during a call_rcu() flood. This commit therefore avoids doing anything if the corresponding no-CBs callback kthread is going full tilt. Otherwise, if advancing callbacks immediately might help and if the leaf rcu_node structure's lock is immediately available, this commit invokes a new variant of rcu_advance_cbs() that advances callbacks only if doing so won't require awakening the grace-period kthread (not to be confused with any of the no-CBs grace-period kthreads). 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.