2a3e3f73a2
This patch modifies the default visibility of the attribute_group for each RAPL event. By default if the grp.is_visible field is NULL, sysfs considers that it must display the attribute group. If the field is not NULL (callback function), then the return value of the callback determines the visibility (0 = not visible). The RAPL attribute groups had the field set to NULL, meaning that unless they failed the probing from perf_msr_probe(), they would be visible. We want to avoid having to specify attribute groups that are not supported by the HW in the rapl_msrs[] array, they don't have an MSR address to begin with. Therefore, we intialize the visible field of all RAPL attribute groups to a callback that returns 0. If the RAPL msr goes through probing and succeeds the is_visible field will be set back to NULL (visible). If the probing fails the field is set to a callback that return 0 (not visible). Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200527224659.206129-4-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.