Currently, execution of 'perf trace' reports the following cryptic
message to the user:
$ perf trace
Couldn't read the raw_syscalls tracepoints information!
Now, it prints a detailed message:
$ perf trace
Error: No permissions to read $debugfs/tracing/events/raw_syscalls
Hint: Change the permissions of debugfs: /sys/kernel/debug
The directory will be present if your kernel was compiled with debugfs
support.
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Arnaldo Carvalho de Melo <a...@ghostprotocols.net>
Signed-off-by: Ramkumar Ramachandra <artag...@gmail.com>
---
tools/perf/builtin-trace.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 71aa3e3..544707a 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -916,14 +916,18 @@ static int trace__run(struct trace *trace, int argc,
const char **argv)
if (perf_evlist__add_newtp(evlist, "raw_syscalls", "sys_enter",
trace__sys_enter) ||
perf_evlist__add_newtp(evlist, "raw_syscalls", "sys_exit",
trace__sys_exit)) {
- fprintf(trace->output, "Couldn't read the raw_syscalls
tracepoints information!\n");
+ fprintf(trace->output, "Error:\tNo permissions to read
$debugfs/tracing/events/raw_syscalls\n");
+ fprintf(trace->output, "Hint:\tChange the permissions of
debugfs: /sys/kernel/debug\n");
+ fprintf(trace->output, "\tThe directory will be present if your
kernel was compiled with debugfs support.\n");
goto out_delete_evlist;
}
if (trace->sched &&
perf_evlist__add_newtp(evlist, "sched", "sched_stat_runtime",
trace__sched_stat_runtime)) {
- fprintf(trace->output, "Couldn't read the sched_stat_runtime
tracepoint information!\n");
+ fprintf(trace->output, "Error:\tNo permissions to read
$debugfs/tracing/events/sched/sched_stat_runtime\n");
+ fprintf(trace->output, "Hint:\tChange the permissions of
debugfs: /sys/kernel/debug\n");
+ fprintf(trace->output, "\tThe directory will be present if your
kernel was compiled with debugfs support.\n");
goto out_delete_evlist;
}
--
1.8.4.477.g5d89aa9
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