X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng%2Fcommands%2Fadd_context.c;h=73aff31130e8e5e5f5489d988bff3583ae8ecc86;hb=af87c45a6179026e263c3a9eb251ccf8ec9537e7;hp=82abc73332ad10b1117a7e95a954f39f4256108e;hpb=852fdd0c1f836d379f8985b8df3186dc6b7daa44;p=lttng-tools.git

diff --git a/src/bin/lttng/commands/add_context.c b/src/bin/lttng/commands/add_context.c
index 82abc7333..73aff3113 100644
--- a/src/bin/lttng/commands/add_context.c
+++ b/src/bin/lttng/commands/add_context.c
@@ -303,33 +303,35 @@ static void usage(FILE *ofp)
 {
 	fprintf(ofp, "usage: lttng add-context -t TYPE\n");
 	fprintf(ofp, "\n");
-	fprintf(ofp, "If no event name is given (-e), the context will be added to the channel\n");
 	fprintf(ofp, "If no channel and no event is given (-c/-e), the context\n");
 	fprintf(ofp, "will be added to all events and all channels.\n");
+	fprintf(ofp, "Otherwise the context will be added only to the channel (-c)\n");
+	fprintf(ofp, "and/or event (-e) indicated.\n");
 	fprintf(ofp, "\n");
 	fprintf(ofp, "Options:\n");
 	fprintf(ofp, "  -h, --help               Show this help\n");
 	fprintf(ofp, "      --list-options       Simple listing of options\n");
-	fprintf(ofp, "  -s, --session            Apply on session name\n");
+	fprintf(ofp, "  -s, --session NAME       Apply on session name\n");
 	fprintf(ofp, "  -c, --channel NAME       Apply on channel\n");
 	fprintf(ofp, "  -e, --event NAME         Apply on event\n");
-	fprintf(ofp, "  -k, --kernel             Apply for the kernel tracer\n");
+	fprintf(ofp, "  -k, --kernel             Apply to the kernel tracer\n");
 #if 0
-	fprintf(ofp, "  -u, --userspace [CMD]    Apply for the user-space tracer\n");
+	fprintf(ofp, "  -u, --userspace [CMD]    Apply to the user-space tracer\n");
 	fprintf(ofp, "                           If no CMD, the domain used is UST global\n");
 	fprintf(ofp, "                           or else the domain is UST EXEC_NAME\n");
 	fprintf(ofp, "  -p, --pid PID            If -u, apply to specific PID (domain: UST PID)\n");
 #else
-	fprintf(ofp, "  -u, --userspace          Apply for the user-space tracer\n");
+	fprintf(ofp, "  -u, --userspace          Apply to the user-space tracer\n");
 #endif
 	fprintf(ofp, "  -t, --type TYPE          Context type. You can repeat that option on\n");
-	fprintf(ofp, "                           the command line.\n");
+	fprintf(ofp, "                           the command line to specify multiple contexts at once.\n");
+	fprintf(ofp, "                           (--kernel preempts --userspace)\n");
 	fprintf(ofp, "                           TYPE can be one of the strings below:\n");
 	print_ctx_type(ofp);
 	fprintf(ofp, "\n");
 	fprintf(ofp, "Example:\n");
 	fprintf(ofp, "This command will add the context information 'prio' and two perf\n"
-			"counters: hardware branch misses and cache misses, to all events\n"
+			"counters (hardware branch misses and cache misses), to all events\n"
 			"in the trace data output:\n");
 	fprintf(ofp, "# lttng add-context -k -t prio -t perf:branch-misses -t perf:cache-misses\n");
 	fprintf(ofp, "\n");
@@ -377,7 +379,7 @@ static int add_context(char *session_name)
 
 	handle = lttng_create_handle(session_name, &dom);
 	if (handle == NULL) {
-		ret = -1;
+		ret = CMD_ERROR;
 		goto error;
 	}
 
@@ -401,7 +403,7 @@ static int add_context(char *session_name)
 		ret = lttng_add_context(handle, &context, opt_event_name,
 				opt_channel_name);
 		if (ret < 0) {
-			fprintf(stderr, "%s: ", type->opt->symbol);
+			ERR("%s: ", type->opt->symbol);
 			continue;
 		} else {
 			MSG("%s context %s added to %s event in %s",
@@ -411,6 +413,8 @@ static int add_context(char *session_name)
 		}
 	}
 
+	ret = CMD_SUCCESS;
+
 error:
 	lttng_destroy_handle(handle);
 
@@ -448,6 +452,11 @@ int cmd_add_context(int argc, const char **argv)
 				ret = -1;
 				goto end;
 			}
+
+			/*
+			 * Look up the index of opt_type in ctx_opts[] first, so we don't
+			 * have to free(type) on failure.
+			 */
 			index = find_ctx_type_idx(opt_type);
 			if (index < 0) {
 				ERR("Unknown context type %s", opt_type);