cd13618937
Konstantin reported problem with default perf record command, which fails on some AMD servers, because of the default maximum precise config. The current fallback mechanism counts on getting ENOTSUP errno for precise_ip fails, but that's not the case on some AMD servers. We can fix this by removing the errno check completely, because the precise_ip fallback is separated. We can just try (if requested by evsel->precise_max) all possible precise_ip, and if one succeeds we win, if not, we continue with standard fallback. Reported-by: Konstantin Kharlamov <Hi-Angel@yandex.ru> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Monnet <quentin.monnet@netronome.com> Cc: Kim Phillips <kim.phillips@amd.com> Link: http://lkml.kernel.org/r/20190703080949.10356-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.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.