linux/tools/perf
Stephane Eranian fc3e4d077d perf stat: Fix default output file
The following commit:

commit 56f3bae706
Author: Jim Cromie <jim.cromie@gmail.com>
Date:   Wed Sep 7 17:14:00 2011 -0600

    perf stat: Add --log-fd <N> option to redirect stderr elsewhere

introduced a bug in the way perf stat outputs the results by default,
i.e., without the --log-fd or --output option. It would default to
writing to file descriptor 0, i.e., stdin. Writing to stdin is allowed
and is equivalent to writing to stdout. However, there is a major
difference for any script that was already capturing the output of perf
stat via redirection:

    perf stat >/tmp/log .... or perf stat 2>/tmp/log ....

They would not capture anything anymore. They would have to do:
    perf stat 0>/tmp/log ...

This breaks compatibility with existing scripts and does not look very
natural.

This patch fixes the problem by looking at output_fd only when it was
modified by user (> 0). It also checks that the value if positive.
Passing --log-fd 0 is ignored.

I would also argue that defaulting to stderr for the results is not the
right thing to do, though this patch does not address this specific
issue.

Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jim Cromie <jim.cromie@gmail.com>
Link: http://lkml.kernel.org/r/20120515111111.GA9870@quad
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-06-11 11:20:21 -03:00
..
arch perf tools: Use scnprintf where applicable 2012-03-14 12:36:19 -03:00
bench perf tool: Fix perf stack to non executable on x86_64 2012-02-06 19:14:17 -02:00
config perf report: Add a simple GTK2-based 'perf report' browser 2012-03-19 15:13:29 -03:00
Documentation Merge branch 'linus' into perf/urgent 2012-05-30 10:59:04 +02:00
python perf python: Use attr.watermark in twatch.py 2012-01-30 18:38:23 -02:00
scripts perf script: Add drop monitor script 2011-09-29 16:41:37 -03:00
ui perf annotate browser: Fix help window entry for navigating to hottest line 2012-05-30 12:31:44 -03:00
util perf tools: Fix endianity swapping for adds_features bitmask 2012-06-11 11:20:01 -03:00
.gitignore perf tools: Ignore auto-generated bison/flex files 2012-04-14 13:50:39 -03:00
builtin-annotate.c perf tools: Convert critical messages to ui__error() 2012-05-29 11:53:42 -03:00
builtin-bench.c perf bench: Also allow measuring memset() 2012-01-24 20:25:32 -02:00
builtin-buildid-cache.c perf buildid: add perfconfig option to specify buildid cache dir 2010-06-05 09:34:04 -03:00
builtin-buildid-list.c perf buildid-list: Work better with pipe mode 2012-05-22 13:03:54 -03:00
builtin-diff.c perf diff: Fix to work with new hists design 2012-03-22 15:12:09 -03:00
builtin-evlist.c perf evlist: Explicititely initialize input_name 2012-05-23 21:47:51 -03:00
builtin-help.c perf options: Type check all the remaining OPT_ variants 2010-05-17 16:22:41 -03:00
builtin-inject.c perf inject: Fix broken perf inject -b 2012-05-22 12:59:28 -03:00
builtin-kmem.c perf: Have perf use the new libtraceevent.a library 2012-04-25 13:28:48 +02:00
builtin-kvm.c perf kvm: Do guest-only counting by default 2012-01-06 15:47:37 -02:00
builtin-list.c perf list: Allow filtering list of events 2011-02-17 15:38:58 -02:00
builtin-lock.c perf: Have perf use the new libtraceevent.a library 2012-04-25 13:28:48 +02:00
builtin-probe.c perf probe: Detect probe target when m/x options are absent 2012-05-11 13:58:53 -03:00
builtin-record.c perf tools: Convert critical messages to ui__error() 2012-05-29 11:53:42 -03:00
builtin-report.c perf callchain: Make callchain cursors TLS 2012-05-31 10:47:12 -03:00
builtin-sched.c perf: Have perf use the new libtraceevent.a library 2012-04-25 13:28:48 +02:00
builtin-script.c perf: Have perf use the new libtraceevent.a library 2012-04-25 13:28:48 +02:00
builtin-stat.c perf stat: Fix default output file 2012-06-11 11:20:21 -03:00
builtin-test.c perf test: Move parse event automated tests to separated object 2012-05-22 11:19:16 -03:00
builtin-timechart.c perf report: Accept fifos as input file 2011-12-23 17:01:03 -02:00
builtin-top.c perf callchain: Make callchain cursors TLS 2012-05-31 10:47:12 -03:00
builtin.h perf tools: Make perf.data more self-descriptive (v8) 2011-10-07 17:01:24 -03:00
command-list.txt perf evlist: New command to list the names of events present in a perf.data file 2011-03-15 11:10:48 -03:00
CREDITS
design.txt perf tools: Update ioctl documentation for PERF_IOC_FLAG_GROUP 2012-05-31 11:38:42 -03:00
Makefile perf tools: Do not use _FORTIFY_SOURCE when DEBUG=1 is specified 2012-05-24 14:48:39 -03:00
MANIFEST perf tools: Fix make tarballs 2012-05-30 15:05:59 -03:00
perf-archive.sh perf archive: Correct cutting of symbolic link 2012-04-14 13:52:15 -03:00
perf.c perf tools: Simplify debugfs mountpoint handling code 2011-11-28 10:11:28 -02:00
perf.h perf record: Fix branch_stack type in perf_record_opts 2012-05-25 18:32:44 -03:00