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

Arnaldo Carvalho de Melo
2011-03-25T18:08:49Z

Em Fri, Mar 25, 2011 at 12:05:50PM -0600, David Ahern escreveu:
> 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 error instead of die which allows the fallback
> from hardware cycles to software clock.

Please use ui__warning(""...) as it will work in the TUI too.

> Signed-off-by: David Ahern <daahern@cisco.com>
> ---
> tools/perf/builtin-record.c | 6 ++++++
> tools/perf/builtin-top.c | 7 +++++++
> 2 files changed, 13 insertions(+), 0 deletions(-)
>
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 6febcc1..73fa8b7 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -282,6 +282,8 @@ 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) {
> + error("%s event is not supported.", event_name(pos));
> } else if (err == EINVAL && sample_id_all_avail) {
> /*
> * Old kernel, no attr->sample_id_type_all field
> @@ -307,6 +309,10 @@ 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..ab27693 100644
> --- a/tools/perf/builtin-top.c
> +++ b/tools/perf/builtin-top.c
> @@ -852,6 +852,9 @@ try_again:
> die("Permission error - are you root?\n"
> "\t Consider tweaking"
> " /proc/sys/kernel/perf_event_paranoid.\n");
> + else if (err == ENOENT)
> + error("%s event is not supported.", event_name(counter));
> +
> /*
> * If it's cycles then fall back to hrtimer
> * based cpu-clock-tick sw counter, which
> @@ -867,6 +870,10 @@ 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