mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-04 08:04:24 -04:00
f4f925dae7
If AMD Last Branch Record Extension Version 2 (LbrExtV2) is detected, convert the requested branch filter (PERF_SAMPLE_BRANCH_* flags) to the corresponding hardware filter value and stash it in the event data when a branch stack is requested. The hardware filter value is also saved in per-CPU areas for use during event scheduling. Hardware filtering is provided by the LBR Branch Select register. It has bits which when set, suppress recording of the following types of branches: * CPL = 0 (Kernel only) * CPL > 0 (Userspace only) * Conditional Branches * Near Relative Calls * Near Indirect Calls * Near Returns * Near Indirect Jumps (excluding Near Indirect Calls and Near Returns) * Near Relative Jumps (excluding Near Relative Calls) * Far Branches Signed-off-by: Sandipan Das <sandipan.das@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/9336af5c9785b8e14c62220fc0e6cfb10ab97de3.1660211399.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.