perf stat: Add --interval-clear option

Adding --interval-clear option to clear the screen before next interval.

Committer testing:

  # perf stat -I 1000 --interval-clear

And, as expected, it behaves almost like:

  # watch -n 0 perf stat -a sleep 1

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20180606221513.11302-4-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 5dfe102..b10a90b 100644 (file)
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -178,6 +178,9 @@ Print count deltas for fixed number of times.
 This option should be used together with "-I" option.
        example: 'perf stat -I 1000 --interval-count 2 -e cycles -a'
 
+--interval-clear::
+Clear the screen before next interval.
+
 --timeout msecs::
 Stop the 'perf stat' session and print count deltas after N milliseconds (minimum: 10 ms).
 This option is not supported with the "-I" option.

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 096ccb2..f1532e3 100644 (file)
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -65,6 +65,7 @@
 #include "util/tool.h"
 #include "util/string2.h"
 #include "util/metricgroup.h"
+#include "util/top.h"
 #include "asm/bug.h"
 
 #include <linux/time64.h>
@@ -173,6 +174,7 @@ static struct cpu_map               *aggr_map;
 static aggr_get_id_t           aggr_get_id;
 static bool                    append_file;
 static bool                    interval_count;
+static bool                    interval_clear;
 static const char              *output_name;
 static int                     output_fd;
 static int                     print_free_counters_hint;
@@ -1704,9 +1706,12 @@ static void print_interval(char *prefix, struct timespec *ts)
        FILE *output = stat_config.output;
        static int num_print_interval;
 
+       if (interval_clear)
+               puts(CONSOLE_CLEAR);
+
        sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, csv_sep);
 
-       if (num_print_interval == 0 && !csv_output) {
+       if ((num_print_interval == 0 && !csv_output) || interval_clear) {
                switch (stat_config.aggr_mode) {
                case AGGR_SOCKET:
                        fprintf(output, "#           time socket cpus");
@@ -1738,7 +1743,7 @@ static void print_interval(char *prefix, struct timespec *ts)
                }
        }
 
-       if (num_print_interval == 0 && metric_only)
+       if ((num_print_interval == 0 && metric_only) || interval_clear)
                print_metric_headers(" ", true);
        if (++num_print_interval == 25)
                num_print_interval = 0;
@@ -2057,6 +2062,8 @@ static const struct option stat_options[] = {
                    "(overhead is possible for values <= 100ms)"),
        OPT_INTEGER(0, "interval-count", &stat_config.times,
                    "print counts for fixed number of times"),
+       OPT_BOOLEAN(0, "interval-clear", &interval_clear,
+                   "clear screen in between new interval"),
        OPT_UINTEGER(0, "timeout", &stat_config.timeout,
                    "stop workload and print counts after a timeout period in ms (>= 10ms)"),
        OPT_SET_UINT(0, "per-socket", &stat_config.aggr_mode,