X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng%2Fcommands%2Fenable_events.c;h=0e6bb55d8bc7b618fadcc830c1a7ee736145a3c3;hp=1a53448c647ebd8469871b916258726649a78c5b;hb=ee8ccafaa999089aa9f6cdc3bc5543cd829c422b;hpb=025faf73cdb6942ebf437dc4c4f6631f0134b128

diff --git a/src/bin/lttng/commands/enable_events.c b/src/bin/lttng/commands/enable_events.c
index 1a53448c6..0e6bb55d8 100644
--- a/src/bin/lttng/commands/enable_events.c
+++ b/src/bin/lttng/commands/enable_events.c
@@ -154,8 +154,8 @@ static void usage(FILE *ofp)
 	fprintf(ofp, "                               TRACE_DEBUG          = 14\n");
 	fprintf(ofp, "                               (shortcuts such as \"system\" are allowed)\n");
 	fprintf(ofp, "    --filter \'expression\'\n");
-	fprintf(ofp, "                           Filter expression on event fields,\n");
-	fprintf(ofp, "                           event recording depends on evaluation.\n");
+	fprintf(ofp, "                           Filter expression on event fields and context.\n");
+	fprintf(ofp, "                           Event recording depends on evaluation.\n");
 	fprintf(ofp, "                           Only specify on first activation of\n");
 	fprintf(ofp, "                           a given event within a session.\n");
 	fprintf(ofp, "                           Filter only allowed when enabling\n");
@@ -175,7 +175,20 @@ static void usage(FILE *ofp)
 	fprintf(ofp, "                           'seqfield1 == \"te*\"'\n");
 	fprintf(ofp, "                           In string literals, the escape character is '\\'.\n");
 	fprintf(ofp, "                           Use '\\*' for the '*' character, and '\\\\' for\n");
-	fprintf(ofp, "                           the '\\' character.\n");
+	fprintf(ofp, "                           the '\\' character. Wildcard match any sequence of,\n");
+	fprintf(ofp, "                           characters including an empty sub-string (match 0 or\n");
+	fprintf(ofp, "                           more characters).\n");
+	fprintf(ofp, "\n");
+	fprintf(ofp, "                           Context information can be used for filtering. The\n");
+	fprintf(ofp, "                           examples below show usage of context filtering on\n");
+	fprintf(ofp, "                           process name (with a wildcard), process ID range, and\n");
+	fprintf(ofp, "                           unique thread ID for filtering. The process and\n");
+	fprintf(ofp, "                           thread ID of running applications can be found under\n");
+	fprintf(ofp, "                           columns \"PID\" and \"LWP\" of the \"ps -eLf\" command.\n");
+	fprintf(ofp, "\n");
+	fprintf(ofp, "                           '$ctx.procname == \"demo*\"'\n");
+	fprintf(ofp, "                           '$ctx.vpid >= 4433 && $ctx.vpid < 4455'\n");
+	fprintf(ofp, "                           '$ctx.vtid == 1234'\n");
 	fprintf(ofp, "\n");
 }
 
@@ -199,7 +212,7 @@ static int parse_probe_opts(struct lttng_event *ev, char *opt)
 		strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
 		ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 		DBG("probe symbol %s", ev->attr.probe.symbol_name);
-		if (strlen(s_hex) == 0) {
+		if (*s_hex == '\0') {
 			ERR("Invalid probe offset %s", s_hex);
 			ret = -1;
 			goto end;
@@ -227,7 +240,7 @@ static int parse_probe_opts(struct lttng_event *ev, char *opt)
 	/* Check for address */
 	ret = sscanf(opt, "%s", s_hex);
 	if (ret > 0) {
-		if (strlen(s_hex) == 0) {
+		if (*s_hex == '\0') {
 			ERR("Invalid probe address %s", s_hex);
 			ret = -1;
 			goto end;
@@ -255,7 +268,7 @@ int loglevel_str_to_value(const char *inputstr)
 	int i = 0;
 	char str[LTTNG_SYMBOL_NAME_LEN];
 
-	while (inputstr[i] != '\0' && i < LTTNG_SYMBOL_NAME_LEN) {
+	while (i < LTTNG_SYMBOL_NAME_LEN && inputstr[i] != '\0') {
 		str[i] = toupper(inputstr[i]);
 		i++;
 	}
@@ -319,8 +332,11 @@ static int enable_events(char *session_name)
 	/* Create lttng domain */
 	if (opt_kernel) {
 		dom.type = LTTNG_DOMAIN_KERNEL;
+		dom.buf_type = LTTNG_BUFFER_GLOBAL;
 	} else if (opt_userspace) {
 		dom.type = LTTNG_DOMAIN_UST;
+		/* Default. */
+		dom.buf_type = LTTNG_BUFFER_PER_PID;
 	} else {
 		ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 		ret = CMD_ERROR;
@@ -494,7 +510,7 @@ static int enable_events(char *session_name)
 
 			if (opt_loglevel) {
 				MSG("Kernel loglevels are not supported.");
-				ret = CMD_UNDEFINED;
+				ret = CMD_UNSUPPORTED;
 				goto error;
 			}
 
@@ -527,7 +543,7 @@ static int enable_events(char *session_name)
 			case LTTNG_EVENT_SYSCALL:
 			default:
 				ERR("Event type not available for user-space tracing");
-				ret = CMD_UNDEFINED;
+				ret = CMD_UNSUPPORTED;
 				goto error;
 			}