1765bb61bb
Per-package perf events are typically registered with a single CPU only, however they can be read across all the CPUs within the package. Currently perf_event_read maps the event CPU according to the topology information to avoid an unnecessary SMP call, however perf_event_read_local deals with hard values and rejects a read with a failure if the CPU is not the one exactly registered. Allow similar mapping within the perf_event_read_local if the perf event in question can support this. This allows users like BPF code to read the package perf events properly across different CPUs within a package. Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230913125956.3652667-1-tero.kristo@linux.intel.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.