[PATCH] perf tools: Emit clearer message for sys_perf_event_open ENOENT return

David Ahern
2011-03-25T19:11:18Z

Resend of patch sent back in January 2011 in light of recent confusion around
unsupported events for a given platform.

Improve sys_perf_event_open ENOENT return handling in top and record, just
like 5a3446b does for stat.

Retry of Arnaldo's patch using ui_warning instead of die which allows the
fallback from hardware cycles to software clock.

Signed-off-by: David Ahern <daahern@cisco.com>
---
tools/perf/builtin-record.c | 7 +++++++
tools/perf/builtin-top.c | 8 ++++++++
2 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 6febcc1..cac275e 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -282,6 +282,9 @@ try_again:
else if (err == ENODEV && cpu_list) {
die("No such device - did you specify"
" an out-of-range profile CPU?\n");
+ } else if (err == ENOENT) {
+ ui__warning("%s event is not supported.\n",
+ event_name(pos));
} else if (err == EINVAL && sample_id_all_avail) {
/*
* Old kernel, no attr->sample_id_type_all field
@@ -307,6 +310,10 @@ try_again:
attr->config = PERF_COUNT_SW_CPU_CLOCK;
goto try_again;
}
+
+ if (err == ENOENT)
+ exit(1);
+
printf("\n");
error("sys_perf_event_open() syscall returned with %d (%s). /bin/dmesg may provide additional information.\n",
err, strerror(err));
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 80c9e06..109e1a0 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -852,6 +852,10 @@ try_again:
die("Permission error - are you root?\n"
"\t Consider tweaking"
" /proc/sys/kernel/perf_event_paranoid.\n");
+ else if (err == ENOENT)
+ ui__warning("%s event is not supported.\n",
+ event_name(counter));
+
/*
* If it's cycles then fall back to hrtimer
* based cpu-clock-tick sw counter, which
@@ -867,6 +871,10 @@ try_again:
attr->config = PERF_COUNT_SW_CPU_CLOCK;
goto try_again;
}
+
+ if (err == ENOENT)
+ exit(1);
+
printf("\n");
error("sys_perf_event_open() syscall returned with %d "
"(%s). /bin/dmesg may provide additional information.\n",
--
1.7.4