b5c4477366
Use the new cpu_dying() state to simplify and fix the balance_push() vs CPU hotplug rollback state. Specifically, we currently rely on notifiers sched_cpu_dying() / sched_cpu_activate() to terminate balance_push, however if the cpu_down() fails when we're past sched_cpu_deactivate(), it should terminate balance_push at that point and not wait until we hit sched_cpu_activate(). Similarly, when cpu_up() fails and we're going back down, balance_push should be active, where it currently is not. So instead, make sure balance_push is enabled below SCHED_AP_ACTIVE (when !cpu_active()), and gate it's utility with cpu_dying(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Link: https://lkml.kernel.org/r/YHgAYef83VQhKdC2@hirez.programming.kicks-ass.net
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.