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

[Arnaldo Carvalho de Melo <acme@ghostprotocols.net>]

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