[tip:perf/core] perf tools: Emit clearer message for sys_perf_event_open ENOENT return

From: tip-bot for David Ahern
Date: Wed Mar 30 2011 - 03:17:17 EST


Commit-ID: ca6a42586fae639ff9e5285d9bdc550fcb1b8d41
Gitweb: http://git.kernel.org/tip/ca6a42586fae639ff9e5285d9bdc550fcb1b8d41
Author: David Ahern <daahern@xxxxxxxxx>
AuthorDate: Fri, 25 Mar 2011 13:11:11 -0600
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Tue, 29 Mar 2011 13:40:27 -0300

perf tools: Emit clearer message for sys_perf_event_open ENOENT return

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.

Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
LKML-Reference: <1301080271-20945-1-git-send-email-daahern@xxxxxxxxx>
Signed-off-by: David Ahern <daahern@xxxxxxxxx>
[ committer note: Some adjustments to make it apply to newer codebase ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-record.c | 10 +++++++++-
tools/perf/builtin-top.c | 6 ++++++
2 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 623695e..db6adec 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -301,11 +301,19 @@ try_again:
&& attr->config == PERF_COUNT_HW_CPU_CYCLES) {

if (verbose)
- warning(" ... trying to fall back to cpu-clock-ticks\n");
+ ui__warning("The cycles event is not supported, "
+ "trying to fall back to cpu-clock-ticks\n");
attr->type = PERF_TYPE_SOFTWARE;
attr->config = PERF_COUNT_SW_CPU_CLOCK;
goto try_again;
}
+
+ if (err == ENOENT) {
+ ui__warning("The %s event is not supported.\n",
+ event_name(pos));
+ exit(EXIT_FAILURE);
+ }
+
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 935fc4f..fc1273e 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -870,6 +870,12 @@ try_again:
goto try_again;
}

+ if (err == ENOENT) {
+ ui__warning("The %s event is not supported.\n",
+ event_name(counter));
+ goto out_err;
+ }
+
ui__warning("The sys_perf_event_open() syscall "
"returned with %d (%s). /bin/dmesg "
"may provide additional information.\n"
--
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