perf tools: Add FIFO file names as alternative options to --control

Enable the --control option to accept file names as an alternative to
file descriptors.

Example:

  $ mkfifo perf.control
  $ mkfifo perf.ack
  $ cat perf.ack &
  [1] 6808
  $ perf record --control fifo:perf.control,perf.ack -- sleep 300 &
  [2] 6810
  $ echo disable > perf.control
  $ Events disabled
  ack

  $ echo enable > perf.control
  $ Events enabled
  ack

  $ echo disable > perf.control
  $ Events disabled
  ack

  $ kill %2
  [ perf record: Woken up 4 times to write data ]
  $ [ perf record: Captured and wrote 0.018 MB perf.data (7 samples) ]

  [1]-  Done                    cat perf.ack
  [2]+  Terminated              perf record --control fifo:perf.control,perf.ack -- sleep 300
  $

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/20200902105707.11491-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
index aa3bed48511b..9911fc6adbfd 100644
--- a/tools/perf/util/stat.h
+++ b/tools/perf/util/stat.h
@@ -136,6 +136,7 @@ struct perf_stat_config {
 	struct rblist		 metric_events;
 	int			 ctl_fd;
 	int			 ctl_fd_ack;
+	bool			 ctl_fd_close;
 };
 
 void perf_stat__set_big_num(int set);