[PATCH] perf stat: Fix default logfd to use stderr

[Robert Richter <robert.richter@amd.com>]

On 29.09.11 18:48:01, Arnaldo Carvalho de Melo wrote:
> From: Jim Cromie <jim.cromie@gmail.com>
> 
> This perf stat option emulates valgrind's --log-fd option, allowing the
> user to send perf results elsewhere, and leaving stderr for use by the
> program under test.  This complements --output file option, and is
> mutually exclusive with it.
> 
>    3>results  perf stat --log-fd 3          -- $cmd
>    3>>results perf stat --log-fd 3 --append -- $cmd
> 
> The perl distro's make test.valgrind target uses valgrind's --log-fd
> option, I've adapted it to invoke perf also, and tested this patch
> there.
> 
> Link: http://lkml.kernel.org/r/1315437244-3788-2-git-send-email-jim.cromie@gmail.com
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

With certain shell redirections this (56f3bae) fails with a log fd
setup failure. Fix below.

-Robert



>From fd83259163c8022f9264a119d5ef7df594702f3a Mon Sep 17 00:00:00 2001
From: Robert Richter <robert.richter@amd.com>
Date: Thu, 7 Jun 2012 17:41:52 +0200
Subject: [PATCH] perf stat: Fix default logfd to use stderr

When running perf-stat in certain shell environments with stdout
redirection there is a logging file descriptor setup failure:

 Failed opening logfd: Invalid argument

Fixing this by setting the default fd to the correct value of 2.

Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: <stable@vger.kernel.org> # 3.2+
Signed-off-by: Robert Richter <robert.richter@amd.com>
---
 tools/perf/builtin-stat.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 2625899..c47e7d3 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -195,7 +195,7 @@ static bool			csv_output			= false;
 static bool			group				= false;
 static const char		*output_name			= NULL;
 static FILE			*output				= NULL;
-static int			output_fd;
+static int			output_fd			=  2;
 
 static volatile int done = 0;
 
-- 
1.7.8.4



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