tools/power turbostat: if --num_iterations, print for specific number of iterations

There's a use case during test to only print specific round of iterations
if --num_iterations is specified, for example, with this patch applied:

turbostat -i 5 -n 4
will capture 4 samples with 5 seconds interval.

[lenb: renamed to --num_iterations from --iterations]

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Reviewed-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 21 insertions, 1 deletions

diff --git a/tools/power/x86/turbostat/turbostat.8 b/tools/power/x86/turbostat/turbostat.8
index 4cffa4a5a2b7..ca9ef7017624 100644
--- a/tools/power/x86/turbostat/turbostat.8
+++ b/tools/power/x86/turbostat/turbostat.8
@@ -67,6 +67,8 @@ The column name "all" can be used to enable all disabled-by-default built-in cou
 .PP
 \fB--interval seconds\fP overrides the default 5.0 second measurement interval.
 .PP
+\fB--num_iterations num\fP number of the measurement iterations.
+.PP
 \fB--out output_file\fP turbostat output is written to the specified output_file.
 The file is truncated if it already exists, and it is created if it does not exist.
 .PP
diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 1cb38c12a8b5..6910773e85a9 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -51,6 +51,7 @@ int *fd_percpu;
 struct timeval interval_tv = {5, 0};
 struct timespec interval_ts = {5, 0};
 struct timespec one_msec = {0, 1000000};
+unsigned int num_iterations;
 unsigned int debug;
 unsigned int quiet;
 unsigned int shown;
@@ -496,6 +497,7 @@ void help(void)
         "--interval sec.subsec  Override default 5-second measurement interval\n"
         "--help         print this help message\n"
         "--list         list column headers only\n"
+        "--num_iterations num   number of the measurement iterations\n"
         "--out file     create or truncate \"file\" for all output\n"
         "--version      print version information\n"
         "\n"
@@ -2763,6 +2765,7 @@ void turbostat_loop()
 {
         int retval;
         int restarted = 0;
+        int done_iters = 0;
 
         setup_signal_handler();
 
@@ -2781,6 +2784,7 @@ restart:
                 goto restart;
         }
         restarted = 0;
+        done_iters = 0;
         gettimeofday(&tv_even, (struct timezone *)NULL);
 
         while (1) {
@@ -2809,6 +2813,8 @@ restart:
                 flush_output_stdout();
                 if (exit_requested)
                         break;
+                if (num_iterations && ++done_iters >= num_iterations)
+                        break;
                 do_sleep();
                 if (snapshot_proc_sysfs_files())
                         goto restart;
@@ -2830,6 +2836,8 @@ restart:
                 flush_output_stdout();
                 if (exit_requested)
                         break;
+                if (num_iterations && ++done_iters >= num_iterations)
+                        break;
         }
 }
 
@@ -5212,6 +5220,7 @@ void cmdline(int argc, char **argv)
                 {"debug",       no_argument,            0, 'd'},        /* internal, not documented */
                 {"enable",      required_argument,      0, 'e'},
                 {"interval",    required_argument,      0, 'i'},
+                {"num_iterations",      required_argument,      0, 'n'},
                 {"help",        no_argument,            0, 'h'},
                 {"hide",        required_argument,      0, 'H'},        // meh, -h taken by --help
                 {"Joules",      no_argument,            0, 'J'},
@@ -5227,7 +5236,7 @@ void cmdline(int argc, char **argv)
 
         progname = argv[0];
 
-        while ((opt = getopt_long_only(argc, argv, "+C:c:Dde:hi:Jo:qST:v",
+        while ((opt = getopt_long_only(argc, argv, "+C:c:Dde:hi:Jn:o:qST:v",
                                 long_options, &option_index)) != -1) {
                 switch (opt) {
                 case 'a':
@@ -5287,6 +5296,15 @@ void cmdline(int argc, char **argv)
                 case 'q':
                         quiet = 1;
                         break;
+                case 'n':
+                        num_iterations = strtod(optarg, NULL);
+
+                        if (num_iterations <= 0) {
+                                fprintf(outf, "iterations %d should be positive number\n",
+                                        num_iterations);
+                                exit(2);
+                        }
+                        break;
                 case 's':
                         /*
                          * --show: show only those specified