Re: [PATCH] perf inject: Fix repipe usage

From: Jiri Olsa <jolsa@redhat.com>
To: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] perf inject: Fix repipe usage
Date: Thu, 1 Apr 2021 16:05:13 +0200	[thread overview]
Message-ID: <YGXTGQwbz0wOWplZ@krava> (raw)
In-Reply-To: <20210401103605.9000-1-adrian.hunter@intel.com>

On Thu, Apr 01, 2021 at 01:36:05PM +0300, Adrian Hunter wrote:
> Since commit 14d3d5405253 ("perf session: Try to read pipe data from file")
> perf inject has started printing "PERFILE2h" when not processing pipes.
> 
> The commit exposed perf to the possiblity that the input is not a pipe but
> the 'repipe' parameter gets used. That causes the printing because perf
> inject sets 'repipe' to true always.
> 
> The 'repipe' parameter of perf_session__new() is used by 2 functions:
> 	- perf_file_header__read_pipe()
> 	- trace_report()
> In both cases, the functions copy data to STDOUT_FILENO when 'repipe' is
> true.
> 
> Fix by setting 'repipe' to true only if the output is a pipe.
> 
> Fixes: e558a5bd8b74 ("perf inject: Work with files")
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>

Acked-by: Jiri Olsa <jolsa@redhat.com>

thanks,
jirka

> ---
>  tools/perf/builtin-inject.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
> index 6fe44d97fde5..ddccc0eb7390 100644
> --- a/tools/perf/builtin-inject.c
> +++ b/tools/perf/builtin-inject.c
> @@ -906,7 +906,7 @@ int cmd_inject(int argc, const char **argv)
>  	}
>  
>  	data.path = inject.input_name;
> -	inject.session = perf_session__new(&data, true, &inject.tool);
> +	inject.session = perf_session__new(&data, inject.output.is_pipe, &inject.tool);
>  	if (IS_ERR(inject.session))
>  		return PTR_ERR(inject.session);
>  
> -- 
> 2.17.1
>