[6/7] libtracefs: Update the libtracefs-sql man page for the new tracefs_synth APIs

Commit Message

Steven Rostedt Aug. 13, 2021, 2:16 a.m. UTC

From: "Steven Rostedt (VMware)" <[e-mail]>

Update the libtracfes-sql man page to have the sqlhist program utilize the
new APIs:

  tracefs_synth_trace()
  tracefs_synth_snapshot()
  tracefs_synth_save()

Signed-off-by: Steven Rostedt (VMware) <[e-mail]>
---
 Documentation/libtracefs-sql.txt    | 105 ++++++++++++++++++++++++++--
 Documentation/libtracefs-synth2.txt |   2 +
 2 files changed, 102 insertions(+), 5 deletions(-)

Patch

diff --git a/Documentation/libtracefs-sql.txt b/Documentation/libtracefs-sql.txt
index 35ccaf5cd1a5..95625157590e 100644
--- a/Documentation/libtracefs-sql.txt
+++ b/Documentation/libtracefs-sql.txt
@@ -305,23 +305,47 @@  EXAMPLE
 
 static void usage(char **argv)
 {
-	fprintf(stderr, "usage: %s [-ed][-n name][-t dir][-f file | sql-command-line]\n"
+	fprintf(stderr, "usage: %s [-ed][-n name][-s][-S fields][-m var][-c var][-T][-t dir][-f file | sql-command-line]\n"
 		"  -n name - name of synthetic event 'Anonymous' if left off\n"
 		"  -t dir - use dir instead of /sys/kernel/tracing\n"
 		"  -e - execute the commands to create the synthetic event\n"
+		"  -m - trigger the action when var is a new max.\n"
+		"  -c - trigger the action when var changes.\n"
+		"  -s - used with -m or -c to do a snapshot of the tracing buffer\n"
+		"  -S - used with -m or -c to save fields of the end event (comma deliminated)\n"
+		"  -T - used with -m or -c to do both a snapshot and a trace\n"
 		"  -f file - read sql lines from file otherwise from the command line\n"
 		"            if file is '-' then read from standard input.\n",
 		argv[0]);
 	exit(-1);
 }
 
-static int do_sql(const char *buffer, const char *name,
-		  const char *trace_dir, bool execute)
+enum action {
+	ACTION_DEFAULT		= 0,
+	ACTION_SNAPSHOT		= (1 << 0),
+	ACTION_TRACE		= (1 << 1),
+	ACTION_SAVE		= (1 << 2),
+	ACTION_MAX		= (1 << 3),
+	ACTION_CHANGE		= (1 << 4),
+};
+
+#define ACTIONS ((ACTION_MAX - 1))
+
+static int do_sql(const char *buffer, const char *name, const char *var,
+		  const char *trace_dir, bool execute, int action,
+		  char **save_fields)
 {
 	struct tracefs_synth *synth;
 	struct tep_handle *tep;
 	struct trace_seq seq;
+	enum tracefs_synth_handler handler;
 	char *err;
+	int ret;
+
+	if ((action & ACTIONS) && !var) {
+		fprintf(stderr, "Error: -s, -S and -T not supported without -m or -c");
+		exit(-1);
+	}
 
 	if (!name)
 		name = "Anonymous";
@@ -345,6 +369,43 @@  static int do_sql(const char *buffer, const char *name,
 	}
 
 	if (tracefs_synth_complete(synth)) {
+		if (var) {
+			if (action & ACTION_MAX)
+				handler = TRACEFS_SYNTH_HANDLE_MAX;
+			else
+				handler = TRACEFS_SYNTH_HANDLE_CHANGE;
+
+			if (action & ACTION_SAVE) {
+				ret = tracefs_synth_save(synth, handler, var, save_fields);
+				if (ret < 0) {
+					err = "adding save";
+					goto failed_action;
+				}
+			}
+			if (action & ACTION_TRACE) {
+				/*
+				 * By doing the trace before snapshot, it will be included
+				 * in the snapshot.
+				 */
+				ret = tracefs_synth_trace(synth, handler, var);
+				if (ret < 0) {
+					err = "adding trace";
+					goto failed_action;
+				}
+			}
+			if (action & ACTION_SNAPSHOT) {
+				ret = tracefs_synth_snapshot(synth, handler, var);
+				if (ret < 0) {
+					err = "adding snapshot";
+ failed_action:
+					perror(err);
+					if (errno == ENODEV)
+						fprintf(stderr, "ERROR: '%s' is not a variable\n",
+							var);
+					exit(-1);
+				}
+			}
+		}
 		tracefs_synth_show(&seq, NULL, synth);
 		if (execute)
 			tracefs_synth_create(NULL, synth);
@@ -375,14 +436,18 @@  int main (int argc, char **argv)
 	int buffer_size = 0;
 	const char *file = NULL;
 	bool execute = false;
+	char **save_fields = NULL;
 	const char *name;
+	const char *var;
+	int action = 0;
+	char *tok;
 	FILE *fp;
 	size_t r;
 	int c;
 	int i;
 
 	for (;;) {
-		c = getopt(argc, argv, "ht:f:en:");
+		c = getopt(argc, argv, "ht:f:en:m:c:sS:T");
 		if (c == -1)
 			break;
 
@@ -398,12 +463,42 @@  int main (int argc, char **argv)
 		case 'e':
 			execute = true;
 			break;
+		case 'm':
+			action |= ACTION_MAX;
+			var = optarg;
+			break;
+		case 'c':
+			action |= ACTION_CHANGE;
+			var = optarg;
+			break;
+		case 's':
+			action |= ACTION_SNAPSHOT;
+			break;
+		case 'S':
+			action |= ACTION_SAVE;
+			tok = strtok(optarg, ",");
+			while (tok) {
+				save_fields = tracefs_list_add(save_fields, tok);
+				tok = strtok(NULL, ",");
+			}
+			if (!save_fields) {
+				perror(optarg);
+				exit(-1);
+			}
+			break;
+		case 'T':
+			action |= ACTION_TRACE | ACTION_SNAPSHOT;
+			break;
 		case 'n':
 			name = optarg;
 			break;
 		}
 	}
 
+	if ((action & (ACTION_MAX|ACTION_CHANGE)) == (ACTION_MAX|ACTION_CHANGE)) {
+		fprintf(stderr, "Can not use both -m and -c together\n");
+		exit(-1);
+	}
 	if (file) {
 		if (!strcmp(file, "-"))
 			fp = stdin;
@@ -434,7 +529,7 @@  int main (int argc, char **argv)
 		}
 	}
 
-	do_sql(buffer, name, trace_dir, execute);
+	do_sql(buffer, name, var, trace_dir, execute, action, save_fields);
 	free(buffer);
 
 	return 0;
diff --git a/Documentation/libtracefs-synth2.txt b/Documentation/libtracefs-synth2.txt
index cfcae7411f58..4c4425325393 100644
--- a/Documentation/libtracefs-synth2.txt
+++ b/Documentation/libtracefs-synth2.txt
@@ -117,6 +117,8 @@  And more errors may have happened from the system calls to the system.
 
 EXAMPLE
 -------
+See *tracefs_sql*(3) for a more indepth use of some of this code.
+
 [source,c]
 --
 #include <stdlib.h>