perf record: Show precise number of samples
After perf record finishes, it prints file size and number of samples in
the file but this info is wrong since it assumes typical sample size of
24 bytes and divides file size by the value.
However as we post-process recorded samples for build-id, it can show
correct number like below. If build-id post-processing is not requested
just omit the wrong number of samples.
$ perf record noploop 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.159 MB perf.data (3989 samples) ]
$ perf report --stdio -n
# To display the perf.data header info, please use --header/--header-only options.
#
# Samples: 3K of event 'cycles'
# Event count (approx.): 3771330663
#
# Overhead Samples Command Shared Object Symbol
# ........ ............ ....... ................ ..........................
#
99.90% 3982 noploop noploop [.] main
0.09% 1 noploop ld-2.17.so [.] _dl_check_map_versions
0.01% 1 noploop [kernel.vmlinux] [k] setup_arg_pages
0.00% 5 noploop [kernel.vmlinux] [k] intel_pmu_enable_all
Reported-by: Milian Wolff <mail@milianw.de>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1422518843-25818-4-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
1 file changed