456ef4c11c
Before we had this unhelpful message: $ perf record --data-page-size sleep 1 Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (cycles:u). /bin/dmesg | grep -i perf may provide additional information. $ Add support to the perf_missing_features variable to remember what caused evsel__open() to fail and then use that information in evsel__open_strerror(). $ perf record --data-page-size sleep 1 Error: Asking for the data page size isn't supported by this kernel. $ Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Stephane Eranian <eranian@google.com> Cc: Will Deacon <will@kernel.org> Link: http://lore.kernel.org/lkml/20201207170759.GB129853@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.