897fa2c38c
In some cases, it's useful to be able to select a random cpu from the intersection of two masks, excluding a particular CPU. For example, in some systems an uncore PMU is shared by a subset of CPUs, and management of this PMU is assigned to some arbitrary CPU in this set. Whenever the management CPU is hotplugged out, we wish to migrate responsibility to another arbitrary CPU which is both in this set and online. Today we can use cpumask_any_and() to select an arbitrary CPU in the intersection of two masks. We can also use cpumask_any_but() to select any arbitrary cpu in a mask excluding, a particular CPU. To do both, we either need to use a temporary cpumask, which is wasteful, or use some lower-level cpumask helpers, which can be unclear. This patch adds a new cpumask_any_and_but() to cater for these cases. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: linux-kernel@vger.kernel.org Signed-off-by: Dawei Li <dawei.li@shingroup.cn> Acked-by: Yury Norov <yury.norov@gmail.com> Link: https://lore.kernel.org/r/20240403155950.2068109-2-dawei.li@shingroup.cn Signed-off-by: Will Deacon <will@kernel.org>
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.