linux/tools
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
..
firewire
hv
include/tools
lguest
lib/traceevent tools lib traceevent: Silence compiler warning on 32bit build 2012-05-26 14:14:58 -03:00
nfsd
perf perf stat: Fix default output file 2012-06-11 11:20:21 -03:00
power sched: Remove stale power aware scheduling remnants and dysfunctional knobs 2012-05-17 13:48:56 +02:00
scripts
testing syscalls, x86: add __NR_kcmp syscall 2012-05-31 17:49:32 -07:00
usb USB: testusb: add path /dev/bus/usb to default search paths for usbfs 2012-05-15 08:41:13 -07:00
virtio
vm tools/vm/page-types.c: cleanups 2012-05-29 16:22:21 -07:00
Makefile