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Date: Sat, 18 Mar 2017 08:23:02 +0900
From: Masami Hiramatsu <mhiramat@kernel.org>
To: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
        <linux-kernel@vger.kernel.org>, <guohanjun@huawei.com>,
        "Jiri Olsa" <jolsa@kernel.org>, Peter Zijlstra <peterz@infradead.org>,
        Wang Nan <wangnan0@huawei.com>
Subject: Re: [PATCH v2] perf probe: Return errno when does not hit any event
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On Fri, 17 Mar 2017 16:16:32 +0800
Kefeng Wang <wangkefeng.wang@huawei.com> wrote:

> On old perf, when using perf probe -d to delete an inexistent event,
> it return errno, eg,
> 
> -bash-4.3# perf probe -d xxx  || echo $?
> Info: Event "*:xxx" does not exist.
>   Error: Failed to delete events.
> 255
> 
> But now perf_del_probe_events() will always set ret = 0, different
> from previous del_perf_probe_events(). After this, it return errno
> again, eg,
> 
> -bash-4.3# ./perf probe -d xxx  || echo $?
> "xxx" does not hit any event.
>   Error: Failed to delete events.
> 254
> 
> And it is more appropriate to return -ENOENT instead of -EPERM.

Looks good to me.

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>

Thanks!

> 
> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Wang Nan <wangnan0@huawei.com>
> 
> Fixes: dddc7ee32fa1 ("perf probe: Fix an error when deleting probes successfully")
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
> 
> v1->v2:
> - Using pr_wanring to show warning infos and drop inappropriate comment
>   suggested by Masami Hiramatsu.
> 
>  tools/perf/builtin-probe.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
> index 1fcebc3..51cdc23 100644
> --- a/tools/perf/builtin-probe.c
> +++ b/tools/perf/builtin-probe.c
> @@ -442,9 +442,9 @@ static int perf_del_probe_events(struct strfilter *filter)
>  	}
>  
>  	if (ret == -ENOENT && ret2 == -ENOENT)
> -		pr_debug("\"%s\" does not hit any event.\n", str);
> -		/* Note that this is silently ignored */
> -	ret = 0;
> +		pr_warning("\"%s\" does not hit any event.\n", str);
> +	else
> +		ret = 0;
>  
>  error:
>  	if (kfd >= 0)
> -- 
> 1.7.12.4
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>