83a43c6221
In some cases, it may be necessary to restrict opening PMU events to a subset of CPUs. E.g. Unified Memory Controller (UMC) PMUs are specific to each active memory channel and the MSR address space for the PERF_CTL and PERF_CTR registers is reused on each socket. Thus, opening events for a specific UMC PMU should be restricted to CPUs belonging to the same socket as that of the UMC. The "cpumask" of the PMU should also reflect this accordingly. Uncore PMUs which require this can use the new group attribute in struct amd_uncore_pmu to set a valid group ID during the scan() phase. Later, during init(), an uncore context for a CPU will be unavailable if the group ID does not match. Signed-off-by: Sandipan Das <sandipan.das@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/937d6d71010a48ea4e069f4904b3116a5f99ecdf.1696425185.git.sandipan.das@amd.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.