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af954f76ee
The perf_event_open might fail due to various reasons, so blindly reducing precise_ip level might not be the best way to deal with it. It seems the kernel return -EOPNOTSUPP when PMU doesn't support the given precise level. Let's try again with the correct error code. This caused a problem on AMD, as it stops on precise_ip of 2 for IBS but user events with exclude_kernel=1 cannot make progress. Let's add the evsel__handle_error_quirks() to this case specially. I plan to work on the kernel side to improve this situation but it'd still need some special handling for IBS. Reviewed-by: James Clark <james.clark@linaro.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Acked-by: Kan Liang <kan.liang@linux.intel.com> Cc: James Clark <james.clark@arm.com> Cc: Atish Patra <atishp@atishpatra.org> Cc: Mingwei Zhang <mizhang@google.com> Cc: Kajol Jain <kjain@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20241016062359.264929-8-namhyung@kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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 reStructuredText 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.