trace-cmd: Add -O to trace-cmd report to pass options to plugins

The -O field now passes options to the plugins. The format is of:

	-O [plugin:]var[=val]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

3 files changed, 30 insertions, 2 deletions

diff --git a/Documentation/trace-cmd-report.1.txt b/Documentation/trace-cmd-report.1.txt
index 148f9d9..9c9a8e7 100644
--- a/Documentation/trace-cmd-report.1.txt
+++ b/Documentation/trace-cmd-report.1.txt
@@ -167,6 +167,17 @@ OPTIONS
 *-q*::
     Quiet non critical warnings.
 
+*-O*::
+    Pass options to the trace-cmd plugins that are loaded.
+
+     -O plugin:var=value
+
+     The 'plugin:' and '=value' are optional. Value may be left off for options
+     that are boolean. If the 'plugin:' is left off, then any variable that matches
+     in all plugins will be set.
+
+     Example:  -O fgraph:tailprint
+
 EXAMPLES
 --------
 
diff --git a/trace-read.c b/trace-read.c
index 0d8f7f1..6e85041 100644
--- a/trace-read.c
+++ b/trace-read.c
@@ -812,6 +812,19 @@ static void add_functions(struct pevent *pevent, const char *file)
         free(buf);
 }
 
+static void process_plugin_option(char *option)
+{
+        char *name = option;
+        char *val = NULL;
+        char *p;
+
+        if ((p = strstr(name, "="))) {
+                *p = '\0';
+                val = p+1;
+        }
+        trace_util_add_option(name, val);
+}
+
 enum {
         OPT_kallsyms    = 253,
         OPT_events      = 254,
@@ -859,7 +872,7 @@ void trace_report (int argc, char **argv)
                         {NULL, 0, NULL, 0}
                 };
 
-                c = getopt_long (argc-1, argv+1, "+hi:feprPNLlEwF:VvTq",
+                c = getopt_long (argc-1, argv+1, "+hi:feprPNLlEwF:VvTqO:",
                         long_options, &option_index);
                 if (c == -1)
                         break;
@@ -912,6 +925,9 @@ void trace_report (int argc, char **argv)
                 case 'l':
                         latency_format = 1;
                         break;
+                case 'O':
+                        process_plugin_option(optarg);
+                        break;
                 case 'v':
                         if (neg)
                                 die("Only 1 -v can be used");
diff --git a/trace-usage.c b/trace-usage.c
index 4b171fe..1497279 100644
--- a/trace-usage.c
+++ b/trace-usage.c
@@ -75,7 +75,7 @@ static struct usage_help usage_help[] = {
                 "report",
                 "read out the trace stored in a trace.dat file",
                 " %s report [-i file] [--cpu cpu] [-e][-f][-l][-P][-L][-N][-r][-E]\\\n"
-                "           [-F filter][-v][-V][-T]\n"
+                "           [-F filter][-v][-V][-T][-O option]\n"
                 "          -i input file [default trace.dat]\n"
                 "          -e show file endianess\n"
                 "          -f show function list\n"
@@ -90,6 +90,7 @@ static struct usage_help usage_help[] = {
                 "          -N do not load any plugins\n"
                 "          -w show wakeup latencies\n"
                 "          -l show latency format (default with latency tracers)\n"
+                "          -O plugin option -O [plugin:]var[=val]\n"
         },
         {
                 "split",