perf util: Add more debug message on failure path

It's helpful for debugging on tracing features.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jeremy Eder <jeder@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>,
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/n/tip-rjysr9ljiesymgk4qblteaty@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 00fd8a8850d3391545981b89ab74c97c62969af0..c567d9f0aa9265d703bd78d5b6e0dfa61ed54d2d 100644 (file)
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2803,8 +2803,10 @@ static int perf_evsel__prepare_tracepoint_event(struct perf_evsel *evsel,
        }
 
        event = pevent_find_event(pevent, evsel->attr.config);
-       if (event == NULL)
+       if (event == NULL) {
+               pr_debug("cannot find event format for %d\n", (int)evsel->attr.config);
                return -1;
+       }
 
        if (!evsel->name) {
                snprintf(bf, sizeof(bf), "%s:%s", event->system, event->name);

diff --git a/tools/perf/util/trace-event-read.c b/tools/perf/util/trace-event-read.c
index 61c7162c31c7431106ea9b00d37083c206eca4c4..27420159bf6944df76eb76a45943a4810e0ba972 100644 (file)
--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -260,39 +260,53 @@ static int read_header_files(struct pevent *pevent)
 
 static int read_ftrace_file(struct pevent *pevent, unsigned long long size)
 {
+       int ret;
        char *buf;
 
        buf = malloc(size);
-       if (buf == NULL)
+       if (buf == NULL) {
+               pr_debug("memory allocation failure\n");
                return -1;
+       }
 
-       if (do_read(buf, size) < 0) {
-               free(buf);
-               return -1;
+       ret = do_read(buf, size);
+       if (ret < 0) {
+               pr_debug("error reading ftrace file.\n");
+               goto out;
        }
 
-       parse_ftrace_file(pevent, buf, size);
+       ret = parse_ftrace_file(pevent, buf, size);
+       if (ret < 0)
+               pr_debug("error parsing ftrace file.\n");
+out:
        free(buf);
-       return 0;
+       return ret;
 }
 
 static int read_event_file(struct pevent *pevent, char *sys,
                            unsigned long long size)
 {
+       int ret;
        char *buf;
 
        buf = malloc(size);
-       if (buf == NULL)
+       if (buf == NULL) {
+               pr_debug("memory allocation failure\n");
                return -1;
+       }
 
-       if (do_read(buf, size) < 0) {
+       ret = do_read(buf, size);
+       if (ret < 0) {
                free(buf);
-               return -1;
+               goto out;
        }
 
-       parse_event_file(pevent, buf, size, sys);
+       ret = parse_event_file(pevent, buf, size, sys);
+       if (ret < 0)
+               pr_debug("error parsing event file.\n");
+out:
        free(buf);
-       return 0;
+       return ret;
 }
 
 static int read_ftrace_files(struct pevent *pevent)
@@ -345,6 +359,7 @@ static int read_saved_cmdline(struct pevent *pevent)
 {
        unsigned long long size;
        char *buf;
+       int ret;
 
        /* it can have 0 size */
        size = read8(pevent);
@@ -352,18 +367,22 @@ static int read_saved_cmdline(struct pevent *pevent)
                return 0;
 
        buf = malloc(size + 1);
-       if (buf == NULL)
+       if (buf == NULL) {
+               pr_debug("memory allocation failure\n");
                return -1;
+       }
 
-       if (do_read(buf, size) < 0) {
-               free(buf);
-               return -1;
+       ret = do_read(buf, size);
+       if (ret < 0) {
+               pr_debug("error reading saved cmdlines\n");
+               goto out;
        }
 
        parse_saved_cmdline(pevent, buf, size);
-
+       ret = 0;
+out:
        free(buf);
-       return 0;
+       return ret;
 }
 
 ssize_t trace_report(int fd, struct trace_event *tevent, bool __repipe)