Load data directory files and provide basic raw dump and aggregated
analysis support of data directories in report mode, still with no
memory consumption optimizations.

READER_MAX_SIZE is chosen based on the results of measurements on
different machines on perf.data directory sizes >1GB. On machines
with big core count (192 cores) the difference between 1MB and 2MB
is about 4%. Other sizes (>2MB) are quite equal to 2MB.
On machines with small core count (4-24) there is no differences
between 1-16 MB sizes. So this constant is 2MB.
Suggested-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Riccardo Mancini <rickyman7@gmail.com>
Signed-off-by: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Riccardo Mancini <rickyman7@gmail.com>
Acked-by: Namhyung Kim <namhyung@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Antonov <alexander.antonov@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/3f10c13a226c0ceb53e88a082f847b91c1ae2c25.1642440724.git.alexey.v.bayduraev@linux.intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>