Stephane Eranian
d5616bac7a
perf/x86/amd: Add idle hooks for branch sampling
On AMD Fam19h Zen3, the branch sampling (BRS) feature must be disabled before entering low power and re-enabled (if was active) when returning from low power. Otherwise, the NMI interrupt may be held up for too long and cause problems. Stopping BRS will cause the NMI to be delivered if it was held up. Define a perf_amd_brs_lopwr_cb() callback to stop/restart BRS. The callback is protected by a jump label which is enabled only when AMD BRS is detected. In all other cases, the callback is never called. Signed-off-by: Stephane Eranian <eranian@google.com> [peterz: static_call() and build fixes] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220322221517.2510440-10-eranian@google.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.
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